Difference between revisions of "UniWiki:Manual of Style/Dates and numbers"

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{{UMoS guideline}}
 
{{UMoS guideline}}
This page guides the presentation of numbers, dates, times, measurements, currencies and similar material in articles. Its aim is to promote clarity and cohesion; this is especially important {{em|within}} an article. The goal is to make the whole UniWiki easier and more intuitive to use.
+
This page guides the presentation of numbers, dates, times, measurements, currencies and similar material in articles. Its aim is to promote clarity and cohesion; this is especially important ''within'' an article. The goal is to make the whole UniWiki easier and more intuitive to use.
  
 
Where this manual provides options, consistency should be maintained within an article unless there is a good reason to do otherwise. If discussion cannot determine which style to use in an article, defer to the style used by the first major contributor.
 
Where this manual provides options, consistency should be maintained within an article unless there is a good reason to do otherwise. If discussion cannot determine which style to use in an article, defer to the style used by the first major contributor.
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Except on pages updated regularly, terms such as {{!xt|now}}, {{!xt|currently}}, {{!xt|to date}}, {{!xt|so far}}, {{!xt|soon}}, and {{!xt|recently}} should usually be avoided in favor of phrases such as {{xt|during the 1990s}}, {{xt|since 2010}}, and {{xt|in August 1969}}. For current and future events, use phrases like {{xt|as of {{CURRENTMONTHNAME}} {{CURRENTYEAR}} }} or {{xt|since the beginning of  {{CURRENTYEAR}} }} to signal the time-dependence of the information.
 
Except on pages updated regularly, terms such as {{!xt|now}}, {{!xt|currently}}, {{!xt|to date}}, {{!xt|so far}}, {{!xt|soon}}, and {{!xt|recently}} should usually be avoided in favor of phrases such as {{xt|during the 1990s}}, {{xt|since 2010}}, and {{xt|in August 1969}}. For current and future events, use phrases like {{xt|as of {{CURRENTMONTHNAME}} {{CURRENTYEAR}} }} or {{xt|since the beginning of  {{CURRENTYEAR}} }} to signal the time-dependence of the information.
  
However, do not replace {{xt|since the beginning of 2005}} with {{xt|as of 2005}} because some information (the {{em|beginning}} of 2005) would be lost.
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However, do not replace {{xt|since the beginning of 2005}} with {{xt|as of 2005}} because some information (the ''beginning'' of 2005) would be lost.
  
 
Relative-time expressions are acceptable for very long periods, such as geological epochs: {{xt|Humans diverged from other primates long ago, but [[wikiquote:Samuel Butler (novelist)#legislature|only recently developed state legislatures]]. }}
 
Relative-time expressions are acceptable for very long periods, such as geological epochs: {{xt|Humans diverged from other primates long ago, but [[wikiquote:Samuel Butler (novelist)#legislature|only recently developed state legislatures]]. }}
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| {{xt|August{{nbsp}}2, 2001}}
 
| {{xt|August{{nbsp}}2, 2001}}
 
| {{xt|Aug{{nbsp}}2, 2001}}
 
| {{xt|Aug{{nbsp}}2, 2001}}
| A comma follows the year unless followed by other punctuation:<ref>See {{Section link|UniWiki:Manual of Style|Commas}}</ref><br />* {{xt|The weather on March 12, 2005, was clear and warm}}<br /> * {{xt|Everyone remembers July{{nbsp}}21, 1969{{snd}}when man first landed on the Moon}}
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| A comma follows the year unless followed by other punctuation:<ref>See {{Section link|UniWiki:Manual of Style|Commas}}</ref><br />* {{xt|The weather on March 12, 2005, was clear and warm}}<br /> * {{xt|Everyone remembers July{{nbsp}}21, 1969 - when man first landed on the Moon}}
 
|-
 
|-
 
| {{xt|2{{nbsp}}August}}
 
| {{xt|2{{nbsp}}August}}
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|-
 
|-
 
| {{!xt|15-04-2007}}<br />{{!xt|04-15-2007}}
 
| {{!xt|15-04-2007}}<br />{{!xt|04-15-2007}}
| Do not use <var>dd</var>-<var>mm</var>-<var>yyyy</var>, <var>mm</var>-<var>dd</var>-<var>yyyy</var> or <var>yyyy</var>-<var>dd</var>-<var>mm</var> formats, as they are ambiguous for some dates<ref>These formats cannot, in general, be distinguished on sight, because there are usages in which 03-04-2007 represents March{{nbsp}}4, and other usages in which it represents April{{nbsp}}3. In contrast there is no common usage in which {{nowrap|2007-04-03}} represents anything other than April{{nbsp}}3.</ref>
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| Do not use <var>dd</var>-<var>mm</var>-<var>yyyy</var>, <var>mm</var>-<var>dd</var>-<var>yyyy</var> or <var>yyyy</var>-<var>dd</var>-<var>mm</var> formats, as they are ambiguous for some dates<ref>These formats cannot, in general, be distinguished on sight, because there are usages in which 03-04-2007 represents March{{nbsp}}4, and other usages in which it represents April{{nbsp}}3. In contrast there is no common usage in which 2007-04-03 represents anything other than April{{nbsp}}3.</ref>
 
|-
 
|-
 
| {{!xt|7/2001}}<br />{{!xt|7-2001}}<br />{{!xt|07-2001}}<br />{{!xt|2001-07}}<br />{{!xt|2001 July}}<br />{{!xt|July of 2001}}
 
| {{!xt|7/2001}}<br />{{!xt|7-2001}}<br />{{!xt|07-2001}}<br />{{!xt|2001-07}}<br />{{!xt|2001 July}}<br />{{!xt|July of 2001}}
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| Do not use these{{nbsp}}formats.
 
| Do not use these{{nbsp}}formats.
 
|-
 
|-
| {{!xt|July''',''' 2001}}
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|
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{{!xt|July''',''' 2001}}
 
| rowspan=2| No comma between month and{{nbsp}}year
 
| rowspan=2| No comma between month and{{nbsp}}year
 
|-
 
|-
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'''Dates in article body text''' should all use the same format: {{xt|She fell ill on 25 June 2005 and died on 28 June}}, but not {{!xt|She fell ill on 25 June 2005 and died on June 28}}.
 
'''Dates in article body text''' should all use the same format: {{xt|She fell ill on 25 June 2005 and died on 28 June}}, but not {{!xt|She fell ill on 25 June 2005 and died on June 28}}.
  
=====<span id="Retaining the existing format"></span>Retaining existing format=====
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=====Retaining existing format=====
{{shortcut|MOS:DATERET|MOS:DATEVAR}}
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{{See also|UniWiki:Manual of Style#Retaining existing styles}}
{{See also|Wikipedia:Manual of Style#Retaining the existing variety|}}
 
  
 
* If an article has evolved using predominantly one format, the whole article should conform to it, unless there are reasons for changing it based on strong national ties to the topic or consensus on the article's talk page.
 
* If an article has evolved using predominantly one format, the whole article should conform to it, unless there are reasons for changing it based on strong national ties to the topic or consensus on the article's talk page.
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* Where an article has shown no clear sign of which format is used, the first person to insert a date is equivalent to "the first major contributor".
 
* Where an article has shown no clear sign of which format is used, the first person to insert a date is equivalent to "the first major contributor".
  
====<span id="Year numbering systems"></span><span id="Eras and other very long periods"></span>Era style====
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====Gregorian and New Eden calendars====
{{shortcut|MOS:ERA|MOS:BCE}}
 
* The default [[calendar era]] is the [[Dionysian era|Western Dionysian era system]], a year numbering system also known as the Western Christian era (represented by {{xt|[[Anno Domini|BC and AD]]}}), or the [[Common Era]] (represented by {{xt|[[Common Era|BCE and CE]]}}).
 
** {{xtn|BC}} and {{xtn|AD}} are the traditional ways of designating eras. {{xtn|BCE}} and {{xtn|CE}} are common in some scholarly texts and in certain topic areas. Either convention may be appropriate for use in Wikipedia articles.
 
*** Do not change the established era style in an article unless there are reasons specific to its content. Seek consensus on the talk page {{em|before}} making the change. Open the discussion under a subhead that uses the word "era". Briefly state why the style is inappropriate for the article in question. A personal or categorical preference for one era style over the other is not justification for making a change.
 
*** {{xtn|BCE}} and {{xtn|CE}} or {{xtn|BC}} and {{xtn|AD}} are written in upper case, unspaced, without a period (full point, <code>.</code>), and separated from the numeric year by a space ({{xt|5{{nbsp}}BC}}, not {{!xt|5BC}}). It is advisable to use a [[Wikipedia:Manual of Style#Non-breaking spaces|non-breaking space]].
 
***  {{xtn|AD}} may appear before or after a year ({{xt|AD{{nbsp}}106}}, {{xt|106{{nbsp}}AD}}); the other abbreviations appear only after ({{xt|106{{nbsp}}CE}}, {{xt|3700{{nbsp}}BCE}}, {{xt|3700{{nbsp}}BC}}).
 
*** In general, do not use {{xtn|CE}} or {{xtn|AD}} unless required to avoid ambiguity (e.g. {{xt|The Norman Conquest took place in 1066}} not {{!xt|1066{{nbsp}}CE}} nor {{!xt|AD{{nbsp}}1066}}) or awkwardness {{nobr|({{xt|January 1, 1 AD}} }} not {{nobr|{{!xt|January 1, 1}}).}}  On the other hand, {{xt|[[Plotinus]] lived at the end of the 3rd century AD}} will avoid confusion. Also, in {{xt|He did not become king until 55{{nbsp}}CE}} the era marker makes it clear that ''55'' does not refer to the person's age (or write {{xt|He did not become king until the year 55}}). If the era is shown for the initial date in a range, then use it for the final date as well: not {{nobr|{{!xt|from 450 BCE to 200}}}} but {{nobr|{{xt|from 450 to 200 BCE}}}} or {{nobr|{{xt|from 450 BCE to 200 BCE}}}} (and definitely {{nobr|{{xt|from 100 BCE to 200 CE}}}}). {{See below|Ranges}}
 
*** Use either the BC{{ndash}}AD or the BCE{{ndash}}CE notation consistently within the same article. Exception: do not change [[MOS:QUOTE|direct quotations]], titles, etc.
 
* '''Uncalibrated (bce) radiocarbon dates:''' [[Calibrated years|Calibrated and uncalibrated]] dates can diverge widely, and some sources distinguish the two only via {{xtn|BCE}} or {{xtn|BC}} (for calibrated dates) versus {{xt|bce}}, {{xtn|bc}} or {{xtn|b.c.}} (uncalibrated). Avoid giving uncalibrated dates except in direct quotations, and even then a footnote or square-bracketed note [like this] should note that the date is uncalibrated or (ideally) give the calibrated date.
 
* '''BP or YBP''': In scientific and academic contexts, BP (before present) or YBP (years before present) are often used. (''Present'' in this context conventionally refers to January{{nbsp}}1, 1950.) Write {{xt|3000 years{{nbsp}}BP}} or {{xt|3000{{nbsp}}YBP}} or {{xt|3000{{nbsp}}years before present}} but not forms such as {{!xt|3000 before present}} and {{!xt|3000 years before the present}}. If one of the abbreviated forms is used, link to ''[[Before present]]'' on first use: {{xt|The Jones artifact was dated to 4000{{nbsp}}[[before present|YBP]], the Smith artifact to 5000 YBP.}}
 
* {{anchor|Other_era_systems}}'''Other era systems''' may be appropriate in an article. In such cases, dates should be followed by a conversion to Dionysian (or vice versa) and the first instance should be linked: {{xt|Qasr-al-Khalifa was built in {{nobr|221{{nbsp}}[[Hijri year|AH]] (836{{nbsp}}CE)}}}}, or {{nobr|{{xt|in 836{{nbsp}}AD (221{{nbsp}}[[Hijri year|AH]])}}}}.
 
** [[Astronomical year numbering]] follows the Common Era and does not require conversion, but the first instance of a non-positive year should still be linked: {{xt|The March equinox passed into Pisces in [[Astronomical year numbering|year{{nbsp}}−67]].}}
 
 
 
====Julian and Gregorian calendars====
 
{{shortcut|MOS:OSNS|MOS:JG}}
 
{{see also|Old Style and New Style dates}}
 
 
 
A date can be given in any appropriate calendar, as long as it is (at the minimum) given in the [[Julian calendar]] or the [[Gregorian calendar]] or both, as described below. For example, an article on the early [[history of Islam]] may give dates in both [[Islamic calendar|Islamic]] and Julian calendars. Where a calendar other than the Julian or Gregorian is used, the article must make this clear.
 
* Current events are dated using the Gregorian calendar.
 
* Dates of events in countries using the Gregorian calendar at that time are given in the Gregorian calendar. This includes some of the [[Gregorian calendar#Timeline|Continent of Europe from 1582]], the [[British Empire]] from 14{{nbsp}}September 1752, and Russia from 14{{nbsp}}February 1918 {{crossref|(see [[Adoption of the Gregorian calendar]])}}.
 
* Dates before 15{{nbsp}}October 1582 (when the Gregorian calendar was first adopted in some places) are normally given in the Julian calendar. The Julian day and month should not be converted to the Gregorian calendar, but the start of the [[Julian year (calendar)|Julian year]] should be assumed to be 1{{nbsp}}January {{crossref|(see below for more details)}}.
 
* Dates for Roman history before 45{{nbsp}}BC are given in the [[Roman calendar]], which was neither Julian nor Gregorian. When (rarely) the Julian equivalent is certain, it may be included.
 
* For dates in early Egyptian and Mesopotamian history, Julian or Gregorian equivalents are often uncertain. Follow the consensus of reliable sources, or indicate their divergence.
 
 
 
The dating method used should follow that used by reliable secondary sources (or if reliable sources disagree, that used most commonly, with an explanatory [[Help:Footnotes|footnote]]).
 
  
At some places and times, the new year began on a date other than 1{{nbsp}}January. For example, in England and its colonies until 1752, the year began on [[Annunciation Day]], 25{{nbsp}}March; {{crossref|see the [[New Year|New Year article]] for other styles}}. In writing about historical events, however, years should be assumed to have begun on 1{{nbsp}}January {{crossref|(see the example of the execution of Charles I in "[[Old Style and New Style dates#Differences in the start of the year|Differences in the start of the year]]")}}; if there is reason to use another start-of-year date, this should be noted.  
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Dates on the UniWiki must be given in the appropriate calendar based on the context of the date or event they are associated with. A date can be given in the [[Wikipedia:Gregorian calendar|Gregorian calendar]], the New Eden calendar, or both, as described below. For example, an article on the early [[Amarr Empire]] will only give dates in the New Eden calendar, while an article about the [[Purity of the Throne]] event may give dates in both calendars.
 +
* Real-world events are dated using the Gregorian calendar.
 +
* In-game events that correspond to real-world dates (such as the Yoiul Festival 2016) or that are the result of player actions are dated using the New Eden calendar when discussing the event in an in-universe context, and using the Gregorian calendar when discussing the event in a real-world or meta context.
 +
* All other in-game events or lore concepts are dated using the New Eden calendar.
  
If there is a need to mention [[Old Style and New Style dates|Old or New Style]] dates in an article (as in the [[Glorious Revolution]]), a footnote should be provided on the first usage, stating whether the New Style refers to a start of year adjustment or to the Gregorian calendar (it can mean either).
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====Ranges====
  
====<span id="Date ranges"></span>Ranges====
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* Use a dash, or a word such as ''from'' or ''between'', but not both: {{xt|from 1881 to 1886}} (not {{!xt|from 1881{{ndash}}1886}});{{nbsp}} {{xt|between June{{nbsp}}1 and July{{nbsp}}3}} (not {{!xt|between June{{nbsp}}1 - July{{nbsp}}3}})
{{anchors|Other date ranges|Dates of birth and death}}{{shortcut|MOS:DOB|MOS:OTHERDATE|MOS:DATERANGE}}
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* A simple '''year{{ndash}}year''' range is written using an en dash (<code>&amp;ndash;</code>) not a hyphen or slash; this dash is usually ''unspaced'' (that is, with no space on either side); and the range's end year is usually given in full:
{{hatnote|Note: A change from a preference for two digits, to a preference for four digits, on the right side of ''year{{ndash}}year'' ranges was implemented in July 2016 per [[Special:Permalink/744053720#WP:DATERANGE ambiguity and stylistic concerns|this RFC]].}}<!-- For the record the change can be seen at https://en.wikipedia.org/?diff=744053720&oldid=744052603 -->
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: &nbsp; &bull; &nbsp; {{xt|1881{{ndash}}1886}};{{nbsp}} {{xt|1881{{ndash}}1992}} (not {{!xt|1881{{ndash}}86}};{{nbsp}} {{!xt|1881 - 1992}})
* Use a dash, or a word such as ''from'' or ''between'', but not both: {{xt|from 1881 to 1886}} (not {{!xt|{{nobr|from 1881{{ndash}}1886}}}});{{nbsp}} {{xt|between June{{nbsp}}1 and July{{nbsp}}3}} (not {{!xt|{{nobr|between June{{nbsp}}1{{snd}}July{{nbsp}}3}}}})
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:: Markup: <code>1881{{t|ndash}}1886</code> or <code>1881&amp;ndash;1886</code>
* A simple '''year{{ndash}}year''' range is written using an en dash (<code>&amp;ndash;</code> or {{tlx|ndash}}) not a hyphen or slash; this dash is usually {{em|unspaced}} (that is, with no space on either side); and the range's end year is usually given in full:
 
: &nbsp; &bull; &nbsp; {{xt|1881{{ndash}}1886}};{{nbsp}} {{xt|1881{{ndash}}1992}} (not {{!xt|1881{{ndash}}86}};{{nbsp}} {{nobr|{{!xt|1881{{snd}}1992}}}})
 
:: {{hanging indent|text=Markup: <code>1881{{t|ndash}}1886</code> or {{nowrap|<code>1881&amp;ndash;1886</code>}} }}
 
 
:* '''Two-digit ending years''' ({{xt|1881{{ndash}}82}}, but never {{!xt|1881{{ndash}}882}} or {{!xt|1881{{ndash}}2}}) ''may'' be used in the case of ''two consecutive years;'' in infoboxes and tables where space is limited (using a single format consistently in any given table column); or in certain topic areas if there is a very good reason, such as matching the established convention of reliable sources.
 
:* '''Two-digit ending years''' ({{xt|1881{{ndash}}82}}, but never {{!xt|1881{{ndash}}882}} or {{!xt|1881{{ndash}}2}}) ''may'' be used in the case of ''two consecutive years;'' in infoboxes and tables where space is limited (using a single format consistently in any given table column); or in certain topic areas if there is a very good reason, such as matching the established convention of reliable sources.
 
:*The '''slash notation''' ({{xt|2005/2006}}) may be used to signify a fiscal year or other special period, if that convention is used in reliable sources.
 
:*The '''slash notation''' ({{xt|2005/2006}}) may be used to signify a fiscal year or other special period, if that convention is used in reliable sources.
  
* Other "simple" ranges use an {{em|unspaced}} en dash as well:
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* Other "simple" ranges use an ''unspaced'' en dash as well:
 
:* '''day{{ndash}}day''': {{xt|5{{ndash}}7{{nbsp}}January 1979}};{{nbsp}} {{xt|January{{nbsp}}5{{ndash}}7, 1979}};{{nbsp}} {{xt|elections were held March 5{{ndash}}8}}
 
:* '''day{{ndash}}day''': {{xt|5{{ndash}}7{{nbsp}}January 1979}};{{nbsp}} {{xt|January{{nbsp}}5{{ndash}}7, 1979}};{{nbsp}} {{xt|elections were held March 5{{ndash}}8}}
:* '''month{{ndash}}month''': {{xt|the 1940 peak period was May{{ndash}}July}};{{nbsp}} {{xt|the peak period was May{{ndash}}July{{nbsp}}1940}};{{nbsp}} (but {{xt|the peak period was {{nobr|May 1940{{snd}}July}} 1940}} uses a {{em|spaced}} en dash; {{crossref|see below}})
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:* '''month{{ndash}}month''': {{xt|the 1940 peak period was May{{ndash}}July}};{{nbsp}} {{xt|the peak period was May{{ndash}}July{{nbsp}}1940}};{{nbsp}} (but {{xt|the peak period was May 1940 - July 1940}} uses a ''spaced'' en dash; ''see below''.
* If at least one of the items on either side of the en dash contains a space, then a {{em|spaced}} en dash ({{tlx|snd}}) is used:
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* If at least one of the items on either side of the en dash contains a space, then a ''spaced'' en dash ({{tl|snd}}) is used:
:* '''between specific dates in different months''': {{xt|They travelled {{nobr|June{{nbsp}}3{{snd}}August{{nbsp}}18,}} 1952}};{{nbsp}} {{xt|They travelled 3{{nbsp}}June{{snd}}18{{nbsp}}August 1952}}  
+
:* '''between specific dates in different months''': {{xt|They travelled June{{nbsp}}3 - August{{nbsp}}18, 1952}};{{nbsp}} {{xt|They travelled 3{{nbsp}}June - 18{{nbsp}}August 1952}}  
 
:* '''between dates in different years''':
 
:* '''between dates in different years''':
:: {{xt|'''Charles Robert Darwin''' (12{{nbsp}}February {{nobr|1809{{snd}}19{{nbsp}}April}} 1882) was an English naturalist{{nbsp}}...}}
+
:: {{xt|'''Charles Robert Darwin''' (12{{nbsp}}February 1809 - 19{{nbsp}}April}} 1882) was an English naturalist{{nbsp}}...
:: {{hanging indent|text=Markup: <code>12{{t|nbsp}}February 1809{{t|snd}}19{{t|nbsp}}April 1882</code> or {{nowrap|<code>12&amp;nbsp;February 1809&amp;nbsp;&amp;ndash; 19&amp;nbsp;April 1882</code>}} }}
+
:: Markup: <code>12{{t|nbsp}}February 1809{{t|snd}}19{{t|nbsp}}April 1882</code> or <code>12&amp;nbsp;February 1809&amp;nbsp;&amp;ndash; 19&amp;nbsp;April 1882</code>  
:: {{xt|'''Abraham Lincoln''' (February{{nbsp}}12, 1809{{snd}}April{{nbsp}}15, 1865) was the 16th President of{{nbsp}}...}}  
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:: {{xt|'''Abraham Lincoln''' (February{{nbsp}}12, 1809 - April{{nbsp}}15, 1865) was the 16th President of{{nbsp}}...}}  
:* '''between months in different years''': {{xt|The exception was in force August {{nobr|1892{{snd}}January}} 1903}};{{nbsp}} {{xt|The Ghent Incursion (March 1822{{snd}}January{{nbsp}}1, 1823) was ended by the New Year's Treaty}}
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:* '''between months in different years''': {{xt|The exception was in force August 1892 - January 1903}};{{nbsp}} {{xt|The Ghent Incursion (March 1822 - January{{nbsp}}1, 1823) was ended by the New Year's Treaty}}
::{{hanging indent|text=Markup: <code>March 1822{{t|snd}}January{{t|nbsp}}1, 1823</code> or {{nowrap|<code>March 1822&amp;nbsp;&amp;ndash; January&amp;nbsp;1, 1823</code>}} }}
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:: Markup: <code>March 1822{{t|snd}}January{{t|nbsp}}1, 1823</code> or <code>March 1822&amp;nbsp;&amp;ndash; January&amp;nbsp;1, 1823</code>
:* '''Where ''circa'' or other modifiers are used''': {{xt|reigned c. 1393{{snd}}1414}} {{See below|Uncertain, incomplete, or approximate dates}}
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:* '''Where ''circa'' or other modifiers are used''': {{xt|reigned c. 1393 - 1414}} ''See {{section link||Uncertain, incomplete, or approximate dates}}, below.''
* Constructions such as {{nobr|{{xt|1982{{ndash}}present}}}} (with unspaced ndash), {{nobr|{{xt|January 1, 2011{{snd}}present}}}} (spaced ndash), or {{nobr|{{xt|January 2011{{snd}}present}}}} (spaced ndash) may be used where appropriate, but other constructions may be more appropriate in prose {{crossref|(see {{section link||Statements likely to become outdated}})}}. In tables and infoboxes where space is limited, ''pres.'' may be used ({{xt|1982{{ndash}}pres.}}).  Do not use incomplete-looking constructions such as {{nobr|{{!xt|1982{{ndash}}}}}} and {{nobr|{{!xt|1982{{ndash}}... }} .}}
+
* Constructions such as {{xt|1982{{ndash}}present}} (with unspaced ndash), {{xt|January 1, 2011 - present}} (spaced ndash), or {{xt|January 2011 - present}} (spaced ndash) may be used where appropriate, but other constructions may be more appropriate in prose ''(see {{section link||Statements likely to become outdated}}). In tables and infoboxes where space is limited, ''pres.'' may be used ({{xt|1982{{ndash}}pres.}}).  Do not use incomplete-looking constructions such as {{!xt|1982{{ndash}}}} and {{!xt|1982{{ndash}}... .}}
* For a '''person still living''': {{xt|'''Serena Williams''' (born September{{nbsp}}26, 1981) is a{{nbsp}}...}}, not {{!xt|(September{{nbsp}}26, 1981{{snd}})}} or {{!xt|(born on September{{nbsp}}26, 1981)}}.
+
* For a '''person still living''': {{xt|'''Serena Williams''' (born September{{nbsp}}26, 1981) is a{{nbsp}}...}}, not {{!xt|(September{{nbsp}}26, 1981 - )}} or {{!xt|(born on September{{nbsp}}26, 1981)}}.
 
:Do not use <code>*</code> to indicate ''born''; use <code>b.</code> only where space is limited e.g. tables and infoboxes; use either <code>born</code> or <code>b.</code> consistently in any given table column.
 
:Do not use <code>*</code> to indicate ''born''; use <code>b.</code> only where space is limited e.g. tables and infoboxes; use either <code>born</code> or <code>b.</code> consistently in any given table column.
 
* Where '''birthdate is unknown''': {{xt|'''John Smith''' (died May{{nbsp}}1, 1622){{nbsp}}...}} or {{xt|'''John Smith''' (died 1622){{nbsp}}...}}
 
* Where '''birthdate is unknown''': {{xt|'''John Smith''' (died May{{nbsp}}1, 1622){{nbsp}}...}} or {{xt|'''John Smith''' (died 1622){{nbsp}}...}}
 
:Do not use <code>†</code> to indicate ''died''; use <code>d.</code> only where space is limited, with consistency within any given table column.
 
:Do not use <code>†</code> to indicate ''died''; use <code>d.</code> only where space is limited, with consistency within any given table column.
 
* An '''overnight period''' may be expressed using a slash between two contiguous dates: {{xt|the night raids of 30/31{{nbsp}}May 1942}} or {{xt|raids of 31{{nbsp}}May{{nbsp}}/ 1{{nbsp}}June 1942}}.
 
* An '''overnight period''' may be expressed using a slash between two contiguous dates: {{xt|the night raids of 30/31{{nbsp}}May 1942}} or {{xt|raids of 31{{nbsp}}May{{nbsp}}/ 1{{nbsp}}June 1942}}.
: Or use an en dash: (unspaced) {{xt|raids of 30{{ndash}}31{{nbsp}}May 1942}};{{nbsp}} (spaced) {{xt|raids of {{nobr|31{{nbsp}}May{{snd}}1{{nbsp}}June}} 1942}}.  
+
: Or use an en dash: (unspaced) {{xt|raids of 30{{ndash}}31{{nbsp}}May 1942}};{{nbsp}} (spaced) {{xt|raids of 31{{nbsp}}May - 1{{nbsp}}June 1942}}.
* The {{tlx|Age}} template can keep ages current in infoboxes and so on:
+
 
: &nbsp; &bull; &nbsp;<code><nowiki>{{age|1989|7|23}}</nowiki></code> returns: {{xt|{{age|1989|7|23}}}}
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====Uncertain, incomplete, or approximate dates====
: &nbsp; &bull; &nbsp;<code><nowiki>{{age|1989|7|23}}-year-old</nowiki></code> returns: {{xt|{{age|1989|7|23}}-year-old}}
 
: &nbsp; &bull; &nbsp;<code><nowiki>{{age|1989|7|23}} years old</nowiki></code> returns: {{xt|{{age|1989|7|23}} years old}}
 
* [[:Category:Date mathematics templates|Date mathematics templates]] are available for other age calculations.
 
  
====Uncertain, incomplete, or approximate dates==== <!--This section/anchor linked to from MOS:DATERANGE.-->
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* To indicate "around", "approximately", or "about", the use of the spaced, unitalicised form {{xt|c.{{nbsp}}1291}} is preferred over {{!xt|circa}}, {{!xt|ca}}, {{!xt|ca.}}, {{!xt|approximately}}, or {{!xt|approx.}}:
{{shortcut|MOS:APPROXDATE|MOS:CIRCA}}
 
* To indicate "around", "approximately", or "about", the use of the spaced, unitalicised form {{xt|c.{{nbsp}}1291}} (or the {{tlx|circa}} template) is preferred over {{!xt|circa}}, {{!xt|ca}}, {{!xt|ca.}}, {{!xt|approximately}}, or {{!xt|approx.}}:
 
 
:&nbsp; &bull; &nbsp; {{xt|At the birth of Roger Bacon (c. 1214){{nbsp}}...}}
 
:&nbsp; &bull; &nbsp; {{xt|At the birth of Roger Bacon (c. 1214){{nbsp}}...}}
:&nbsp; &bull; &nbsp; {{xt|'''John Sayer''' ({{circa}} 1750{{snd}}2{{nbsp}}October 1818){{nbsp}}...}}
+
* Where both endpoints of a range are approximate, c. should appear before each date:
:&nbsp; &bull; &nbsp; {{xt|the Igehalkid dynasty of Elam, {{circa|1400{{nbsp}}BC}}{{nbsp}}...}}
+
:&nbsp; &bull; &nbsp; {{xt|'''Dionysius Exiguus''' (c. 470 - c. 540){{nbsp}}...}} (not {{!xt|'''Dionysius Exiguus''' (c. 470 - 540){{nbsp}}...}})
* Where both endpoints of a range are approximate, c. should appear before each date (the two-argument form of {{tlx|circa}} does this):
+
:&nbsp; &bull; &nbsp; {{xt|'''Rameses III''' (reigned c. 1180 &ndash; c. 1150{{nbsp}}BCE){{nbsp}}...}} (not {{!xt|'''Rameses III''' (reigned c. 1180 - 1150{{nbsp}}BCE){{nbsp}}...}})
:&nbsp; &bull; &nbsp; {{xt|'''Dionysius Exiguus''' ({{circa}} 470{{snd}}{{circa}} 540){{nbsp}}...}} (not {{!xt|'''Dionysius Exiguus''' ({{circa}} 470{{snd}}540){{nbsp}}...}})
+
* When a date is known to be either of two years (e.g. from a [[Wikipedia:Regnal years of English monarchs|regnal]] or [[Wikipedia:Hijri year|AH]] year conversion, or a known age at death):
:&nbsp; &bull; &nbsp; {{xt|'''Rameses III''' (reigned {{circa|1180|1150{{nbsp}}BCE}}){{nbsp}}...}} (not {{!xt|'''Rameses III''' (reigned {{circa}} 1180{{snd}}1150{{nbsp}}BCE){{nbsp}}...}})
 
* Where birth/death limits have been inferred from known dates of activity:
 
:&nbsp; &bull; &nbsp; {{xt|'''Offa of Mercia''' (before 734{{snd}}26{{nbsp}}July 796){{nbsp}}...}}
 
:&nbsp; &bull; &nbsp; {{xt|'''Robert Menli Lyon''' (1789{{snd}}after 1863){{nbsp}}...}}
 
:&nbsp; &bull; &nbsp; {{xt|'''Ambrose Gwinnett Bierce''' (June 24, 1842{{snd}}after December 26, 1913){{nbsp}}...}}<!-- Relationship between "before/after" and "fl." needs to be clarified. -->
 
* When a person is known to have been active ("flourishing") during certain years, {{xt|fl.}}, <code><nowiki>[[Floruit|fl.]]</nowiki></code>, or {{tlx|fl.}} may be used:
 
:&nbsp; &bull; &nbsp; {{xt|'''Jacobus Flori''' ([[floruit|fl.]] 1571–1588) ...}}
 
: The linked forms should not be used on disambiguation pages, and "active" followed by the range is a better alternative for occupations not relating to the composition of works, whether it be musical, grammatical, historical, or any other such work.
 
* When a date is known to be either of two years (e.g. from a [[Regnal years of English monarchs|regnal]] or [[Hijri year|AH]] year conversion, or a known age at death):
 
 
: &nbsp; &bull; &nbsp; {{xt|'''Anne Smith''' (born 1912 or 1913; died 2013){{nbsp}}...}}
 
: &nbsp; &bull; &nbsp; {{xt|'''Anne Smith''' (born 1912 or 1913; died 2013){{nbsp}}...}}
 
* Other forms of uncertainty should be expressed in words, either in article text or in a footnote: {{xt|April{{nbsp}}14, 1224 (unattested date)}}. Do not use a question mark ({{!xt|1291?}}), because it fails to communicate the nature of the uncertainty.
 
* Other forms of uncertainty should be expressed in words, either in article text or in a footnote: {{xt|April{{nbsp}}14, 1224 (unattested date)}}. Do not use a question mark ({{!xt|1291?}}), because it fails to communicate the nature of the uncertainty.
* Ranges in which {{xt|c.}}, {{xt|after}}, {{xt|fl.}} or similar forms appear{{mdashb}}whether on one or both sides{{mdashb}}employ a ''spaced'' endash (<code><nowiki>{{snd}}</nowiki></code>) and ideally a nonbreaking space should follow very short modifiers such as {{xt|c.}} and {{xt|fl.}}. ''Markup:'' {{nobr|<code><nowiki>1896{{snd}}after 1954</nowiki></code>}}, {{nobr|<code><nowiki>{{c.}}{{nbsp}}470{{snd}}{{c.}}{{nbsp}}540</nowiki></code>}}, {{nobr|<code><nowiki>{{c.|470|540}}</nowiki></code>}}
+
* Ranges in which {{xt|c.}}, {{xt|after}}, {{xt|fl.}} or similar forms appear&mdash;whether on one or both sides&mdash;employ a ''spaced'' endash (<code><nowiki> - </nowiki></code>) and ideally a nonbreaking space should follow very short modifiers such as {{xt|c.}} and {{xt|fl.}}. ''Markup:'' <code><nowiki>1896 - after 1954</nowiki></code>
  
 
===<span id="Day, month and season names"></span><span id="Longer periods"></span><span id="Other periods"></span>Other===
 
===<span id="Day, month and season names"></span><span id="Longer periods"></span><span id="Other periods"></span>Other===
Line 252: Line 213:
  
 
====Seasons====
 
====Seasons====
{{shortcut|MOS:SEASON}}
+
 
 
* Seasons are uncapitalized ({{xt|a hot summer}}) except when personified: {{xt|Old Man Winter's bleak greys relent as Spring begins to show her colors}}.
 
* Seasons are uncapitalized ({{xt|a hot summer}}) except when personified: {{xt|Old Man Winter's bleak greys relent as Spring begins to show her colors}}.
* Using seasons to refer to a particular time of year ({{!xt|winter 1995}}) is ambiguous for two reasons:
+
* All seasons used should refer to seasons in the northern hemisphere, as that is where CCP is located, and is thus the reference point for game development, patch releases, and other events.
** the same names are used for both [[northern hemisphere]] and [[southern hemisphere]] seasons, which occur six months apart, and;
+
** In the rare case where an article references seasons in relation to a specific country or region ''not'' in the northern hemisphere, the appropriate season for that location may be used.
** areas near the equator have only [[Wet season|wet]] and [[dry season]]s.
 
:Unambiguous alternatives include {{xt|early 1995}};{{nbsp}} {{xt|the first quarter of 1995}};{{nbsp}} {{xt|January to March 1995}};{{nbsp}} {{xt|spent the southern summer in Antarctica}}.
 
* Referring to a season by name is appropriate when it is part of a formal or conventional name or designation ({{xt|annual mid-winter festival}};{{nbsp}} {{xt|the autumn harvest}};{{nbsp}} {{xt|2018 Winter Olympics}};{{nbsp}} {{xt|''Times'' Fall Books Supplement}};{{nbsp}} {{xt|Details appeared in ''Quarterly Review'', Summer&nbsp;2015}};{{nbsp}} {{xt|The Court's winter term}}).
 
 
 
====Decades====
 
{{shortcut|MOS:DECADE}}
 
* To refer to a decade as a chronological period ''per se'' (not with reference to a social era or cultural phenomenon) always use four digits ({{xt|the{{nbsp}}1980s}}, but not {{!xt|the{{nbsp}}1980's}} or {{!xt|the{{nbsp}}1980{{nbh}}ies}}, and {{em|definitely}} not {{!xt|the{{nbsp}}1980s'}}).
 
:* Prefixes should be hyphenated ({{xt|the{{nbsp}}mid{{nbh}}1980s}};{{nbsp}} {{xt|pre{{nbh}}1960s social attitudes}}).<!-- Nonbreaking hyphens {{nbh}} are used in some examples to keep them from being fragmented over linebreaks here in MOS; that's not to say {{nbh}} ought to be used in "real life" in such situations. -->
 
* For a social era or cultural phenomenon associated with a particular decade:
 
:* Two digits (with a preceding apostrophe) may be used as an alternative to four digits, {{em|but only if this is a well-established phrase seen in reliable sources}} ({{xt|the{{nbsp}}Roaring{{nbsp}}'20s}},{{nbsp}} {{xt|the{{nbsp}}Gay{{nbsp}}'90s}},{{nbsp}} {{xt|condemning the '60s counterculture}}, but {{xt|grew up in 1960s Boston, moving to Dallas in{{nbsp}}1971}}, and do not write {{!xt|the{{nbsp}}90's}};{{nbsp}} {{!xt|the{{nbsp}}90s}};{{nbsp}} or {{!xt|the{{nbsp}}90s'}}).
 
:* A third alternative (where seen in reliable sources) is to spell the decade out, capitalized: {{xt|changing attitudes of the Sixties}}
 
 
 
====<span id="centuries"></span><span id="millennia"></span>Centuries and millennia====
 
{{shortcut|MOS:CENTURY|MOS:MILLENNIUM}}
 
* Treat the 1st century AD as years {{nobr|1{{ndash}}100}}, the 17th century as {{nobr|1601{{ndash}}1700}}, and the second millennium as {{nobr|1001{{ndash}}2000}}; similarly, the 1st century BC/BCE was {{nobr|100{{ndash}}1}} BC/BCE, the 17th century was {{nobr|1700{{ndash}}1601}} BC/BCE, and the second millennium {{nobr|2000{{ndash}}1001}} BC/BCE.
 
** The 18th century ({{nobr|1701{{ndash}}1800}}) and the 1700s ({{nobr|1700{{ndash}}1799}}) are not the same period.
 
** When using forms such as {{xt|the 1900s}}, ensure that there is no ambiguity as to whether the century or just its first decade is meant.
 
** Note that the sequence of years runs {{xt|...{{nbsp}}2{{nbsp}}BC, 1{{nbsp}}BC, 1{{nbsp}}AD, 2{{nbsp}}AD{{nbsp}}...}}{{snd}}there is no "[[Year 0|year 0]]".
 
* Centuries and millennia are identified using either figures ({{nobr|{{xt|the 18th century}}}}, not {{!xt|XVIII{{nbsp}}century}}) or words ({{xt|the second millennium}}).<!-- Actually, I wonder whether "1st millennium" and "2nd millennium" are really appropriate – they look funny. --> When used adjectivally they contain a hyphen ({{xt|nineteenth-century painting}} or {{xt|{{nobr|19th-century}} painting}}). Do not capitalize ({{!xt|the best Nineteenth-century paintings}};{{nbsp}} {{!xt|during the Nineteenth Century}}).
 
:* {{crossref|See {{section link|WP:Manual of Style|En dashes}} for use of hyphens and dashes in obscure situations.}}
 
 
 
====<span id="Abbreviations for long periods of time"></span>Long periods of time====
 
* When the term is frequent, combine {{xtn|yr}}{{nbsp}}(years) or {{xtn|ya}}{{nbsp}}(years ago) with {{xtn|k}}{{nbsp}}(thousand): {{xtn|kya}}, {{xtn|kyr}}; {{xtn|M}}{{nbsp}}(million): {{xtn|Mya}}, {{xtn|Myr}}; and {{xtn|b}}{{nbsp}}([[Long and short scales|short-scale]] billion): {{xtn|bya}}, {{xtn|byr}}. {{Crossref|(See [[Year#Abbreviations yr and ya]] for more information.)}}
 
* In academic contexts, [[International System of Units|SI]] annus-based units are often used: {{xtn|ka}}{{nbsp}}(kiloannus), {{xtn|Ma}}{{nbsp}}(megaannus), and {{xtn|Ga}}{{nbsp}}(gigaannus). {{Crossref|(See [[Year#SI prefix multipliers]] for more information.)}}
 
* Show the meaning parenthetically, and consider linking to the appropriate section of the [[Year]] article {{crossref|(see links above)}} on first occurrence and where the use is a standalone topic of interest. In source quotations, use square brackets: {{xt|"a measured Libby radiocarbon date of 35.1{{nbsp}}mya [million years ago] required calibration ..."}}
 
  
 
==Numbers==
 
==Numbers==
 
===Numbers as figures or words===
 
===Numbers as figures or words===
{{shortcut|WP:NUMERAL|MOS:NUMERAL|WP:SPELL09|MOS:SPELL09}}
+
''See
{{crossref|See also information on specific situations, elsewhere in this guideline.}}
+
also information on specific situations, elsewhere in this guideline.''
  
 
Generally, in article text:
 
Generally, in article text:
 
* Integers from zero to nine are spelled out in words.
 
* Integers from zero to nine are spelled out in words.
* Integers greater than nine {{em|expressible in one or two words}} may be expressed either in numerals or in words ({{xt|16}} or {{xt|sixteen}}, {{xt|84}} or {{nobr|{{xt|eighty-four}}}}, {{xt|200}} or {{nobr|{{xt|two hundred}}}}). Numbers between 21 and 99 are hyphenated (including when part of a larger number): {{nobr|{{xt|fifty-six}}}} or {{nobr|{{xt|fifty-six thousand}}}} but {{xt|five{{nbsp}}hundred}} or {{xt|five{{nbsp}}thousand}}.
+
* Integers greater than nine ''expressible in one or two words'' may be expressed either in numerals or in words ({{xt|16}} or {{xt|sixteen}}, {{xt|84}} or {{xt|eighty-four}}, {{xt|200}} or {{xt|two hundred}}). Numbers between 21 and 99 are hyphenated (including when part of a larger number): {{xt|fifty-six}} or {{xt|fifty-six thousand}} but {{xt|five{{nbsp}}hundred}} or {{xt|five{{nbsp}}thousand}}.
* Other numbers are given in numerals ({{xt|3.75}}, {{xt|544}}) or in forms such as {{xt|21{{nbsp}}million}}. Markup: {{nowrap|<code><nowiki>21{{nbsp}}million</nowiki></code>}}
+
* Other numbers are given in numerals ({{xt|3.75}}, {{xt|544}}) or in forms such as {{xt|21{{nbsp}}million}}. Markup: <code><nowiki>21{{nbsp}}million</nowiki></code>
:* "billion" and "trillion" are understood to represent their [[Long and short scales|short-scale]] values of 10<sup>9</sup>{{nbsp}}(1,000,000,000) and 10<sup>12</sup>{{nbsp}}(1,000,000,000,000), respectively. Keep this in mind when translating articles from non-English Wikipedias, or using material from non-English sources.
+
:* "billion" and "trillion" are understood to represent their [[Wikipedia:Long and short scales|short-scale]] values of 10<sup>9</sup>{{nbsp}}(1,000,000,000) and 10<sup>12</sup>{{nbsp}}(1,000,000,000,000), respectively. Keep this in mind when using material from non-English sources.
:* {{xt|M}} (unspaced) or {{xt|bn}} (unspaced) respectively may be used for "million" or "billion" after a number, when the word has been spelled out at the first occurrence ({{xt|She received &pound;70{{nbsp}}million and her son &pound;10M}}).<!-- This needs to be coordinated with text in units tables re nonuse of M (for 1000) MM, etc. -->
+
:* {{xt|M}} (unspaced) or {{xt|bn}} (unspaced) respectively may be used for "million" or "billion" after a number, when the word has been spelled out at the first occurrence ({{xt|She received &pound;70{{nbsp}}million and her son &pound;10M}}).
:*SI prefixes and symbols, such as {{xtn|mega-}}{{nbsp}}({{xtn|M}}), {{xtn|giga-}}{{nbsp}}({{xtn|G}}) and {{xtn|tera-}}{{nbsp}}({{xtn|T}}), should be used only with units of measure as appropriate to the field, and not to express large quantities in other contexts ({{!xt|of the population of 1.3G{{nbsp}}people, 300{{nbsp}}megadeaths would be expected}}).
+
:*SI prefixes and symbols, such as '''mega-'''{{nbsp}}('''M'''), '''giga-'''{{nbsp}}('''G''') and '''tera-'''{{nbsp}}('''T'''), should be used only with units of measure as appropriate to the field, and not to express large quantities in other contexts ({{!xt|of the population of 1.3G{{nbsp}}people, 300{{nbsp}}megadeaths would be expected}}).
:* Sometimes, the [[Wikipedia:Manual of Style#National varieties of English|variety of English]] used in an article may necessitate the use of a numbering system other than the Western thousands-based system. For example, the [[South Asian numbering system]] is conventionally used in [[South Asian English]]. In those situations, link the first spelled-out instance of each quantity (e.g. <code><nowiki>[[crore]]</nowiki></code>, which yields [[crore]]). (If no instances are spelled out, provide a note after the first instance directing the reader to the article about the numbering system.) Also, provide a conversion to Western numbers for the first instance of each quantity, and provide conversions for subsequent instances if they do not overwhelm the content of the article. For example, write {{xt|three [[crore]] (thirty million)}}. Group digits in Western thousands-based style (e.g., {{xt|30,000,000}}; not {{!xt|3,00,00,000}}); {{crossref|see {{section link||Delimiting (grouping of digits)}}, below}}. (Note that the variety of English does not uniquely determine the method of numbering in an article. Other considerations, such as conventions used in mathematics, science and engineering, may also apply, and the choice and order of formats and conversions is a matter of editorial discretion and consensus.)
 
  
{{anchor|Numeral notes}}{{shortcut|WP:NUMNOTES}}
 
 
Notes and exceptions:
 
Notes and exceptions:
  
 
* In tables and infoboxes, quantities are expressed in figures ({{xt|'''Years in office:'''{{nbsp}}5}}); but numbers within a table's explanatory text and comments follow the general rule.
 
* In tables and infoboxes, quantities are expressed in figures ({{xt|'''Years in office:'''{{nbsp}}5}}); but numbers within a table's explanatory text and comments follow the general rule.
* Numbers in mathematical formulae are never spelled out ({{xt|3{{nbsp}}<{{nbsp}}π{{nbsp}}<{{nbsp}}22/7}}, not {{nobr|{{!xt|three < π < 22 sevenths}}}}).
+
* Numbers in mathematical formulae are never spelled out ({{xt|3{{nbsp}}<{{nbsp}}π{{nbsp}}<{{nbsp}}22/7}}, not {{!xt|three < π < 22 sevenths}}).
 
* Comparable quantities should be all spelled out or all in figures:
 
* Comparable quantities should be all spelled out or all in figures:
 
: &nbsp; &bull; &nbsp;{{xt|five cats and thirty-two dogs}}, not {{!xt|five cats and 32 dogs}}
 
: &nbsp; &bull; &nbsp;{{xt|five cats and thirty-two dogs}}, not {{!xt|five cats and 32 dogs}}
 
: &nbsp; &bull; &nbsp;{{xt|86{{nbsp}}men and 103{{nbsp}}women}}, not {{!xt|eighty-six men and 103 women}}  
 
: &nbsp; &bull; &nbsp;{{xt|86{{nbsp}}men and 103{{nbsp}}women}}, not {{!xt|eighty-six men and 103 women}}  
 
: &nbsp; &bull; &nbsp;{{xt|There were 3 winners and 206 losers}}, even though ''3'' would normally be given as ''three''; or {{xt|Three won and two hundred six lost}} (or ''two hundred '''and''' six'' in British English), even though ''two hundred six'' would normally be given as ''206''); but not {{!xt|There were three winners and 206 losers}}.
 
: &nbsp; &bull; &nbsp;{{xt|There were 3 winners and 206 losers}}, even though ''3'' would normally be given as ''three''; or {{xt|Three won and two hundred six lost}} (or ''two hundred '''and''' six'' in British English), even though ''two hundred six'' would normally be given as ''206''); but not {{!xt|There were three winners and 206 losers}}.
* But adjacent quantities not comparable should usually be in {{em|different formats:}} {{nobr|{{xt|twelve 90-minute volumes}}}} or {{nobr|{{xt|12 ninety-minute volumes}}}}, not {{nobr|{{!xt|12 90-minute volumes}}}} or {{nobr|{{!xt|twelve ninety-minute volumes}}}}.
+
* But adjacent quantities not comparable should usually be in ''different formats:'' {{xt|twelve 90-minute volumes}} or {{xt|12 ninety-minute volumes}}, not {{!xt|12 90-minute volumes}} or {{!xt|twelve ninety-minute volumes}}.
:* Avoid awkward juxtapositions: {{xt|On February 25, 2011, twenty-one more were chosen}}, not {{nobr|{{!xt|On February 25, 2011, 21 more were chosen}}}}.
+
:* Avoid awkward juxtapositions: {{xt|On February 25, 2011, twenty-one more were chosen}}, not {{!xt|On February 25, 2011, 21 more were chosen}}.
 
* Personal ages are typically stated in figures ({{xt|8-year-old child}}) except for large, approximate values ({{xt|69-million-year-old fossil}}).
 
* Personal ages are typically stated in figures ({{xt|8-year-old child}}) except for large, approximate values ({{xt|69-million-year-old fossil}}).
 
* Sometimes figures and words carry different meanings; for example {{xt|Every locker except one was searched}} implies there is a single exception (without specifying which), while {{xt|Every locker except{{nbsp}}1 was searched}} means that only locker number{{nbsp}}1 was not searched.
 
* Sometimes figures and words carry different meanings; for example {{xt|Every locker except one was searched}} implies there is a single exception (without specifying which), while {{xt|Every locker except{{nbsp}}1 was searched}} means that only locker number{{nbsp}}1 was not searched.
* Proper names, technical terms, and the like are never altered: {{xt|''[[Seven Samurai]]''}};{{nbsp}} {{xt|''[[The Sixth Sense]]''}};{{nbsp}} {{xt|5{{nbsp}}Channel Street}};{{nbsp}} {{xt|Channel{{nbsp}}5}};{{nbsp}} {{xt|Chanel No.{{nbsp}}5}};{{nbsp}} {{xt|Fourth Estate}};{{nbsp}} {{xt|''[[The Third Man]]''}};{{nbsp}} {{xt|Second Judicial District}};{{nbsp}} {{xt|First Amendment}};{{nbsp}} {{xt|''[[Zero Hour!]]''}};{{nbsp}}  {{xt|''[[Less Than Zero (film)|Less Than Zero]]''}}
+
* Proper names, technical terms, and the like are never altered: {{xt|''[[Wikipedia:Seven Samurai|Seven Samurai]]''}};{{nbsp}} {{xt|''[[Wikipedia:The Sixth Sense|The Sixth Sense]]''}};{{nbsp}} {{xt|5{{nbsp}}Channel Street}};{{nbsp}} {{xt|Channel{{nbsp}}5}};{{nbsp}} {{xt|Chanel No.{{nbsp}}5}};{{nbsp}} {{xt|Fourth Estate}};{{nbsp}} {{xt|''[[Wikipedia:The Third Man|The Third Man]]''}};{{nbsp}} {{xt|Second Judicial District}};{{nbsp}} {{xt|First Amendment}};{{nbsp}} {{xt|''[[Wikipedia:Zero Hour|Zero Hour!]]''}};{{nbsp}}  {{xt|''[[Wikipedia:Less Than Zero (film)|Less Than Zero]]''}}
  
 
* Avoid beginning a sentence with figures:
 
* Avoid beginning a sentence with figures:
:&nbsp; &bull; &nbsp; Not {{!xt|There were many matches'''.''' 23 ended in a draw}},{{break}}
+
:&nbsp; &bull; &nbsp; Not {{!xt|There were many matches'''.''' 23 ended in a draw}},
 
:&nbsp; &nbsp; &nbsp; but {{xt|There were many matches''';''' 23{{nbsp}}ended in a draw}} or {{xt|There were many matches'''.''' Twenty-three ended in a draw}}.
 
:&nbsp; &nbsp; &nbsp; but {{xt|There were many matches''';''' 23{{nbsp}}ended in a draw}} or {{xt|There were many matches'''.''' Twenty-three ended in a draw}}.
:&nbsp; &bull; &nbsp; Not {{nowrap|{{!xt|1945 and 1950 saw crucial elections}}}} (nor {{nowrap|{{!xt|Nineteen forty-five and 1950 saw crucial elections}}}}{{snd}}because comparable numbers should be both written in words or both in figures) but {{nowrap|{{xt|The elections of 1945 and 1950 were crucial.}}}}<!-- Examples still need work, and need something about "nineteen forty-five"-type years. -->
+
:&nbsp; &bull; &nbsp; Not {{!xt|1945 and 1950 saw crucial elections}} (nor {{!xt|Nineteen forty-five and 1950 saw crucial elections}} - because comparable numbers should be both written in words or both in figures) but {{xt|The elections of 1945 and 1950 were crucial.}}
 
:* Exception: Where a proper name, technical term, etc., itself beginning with a numeral, opens the sentence ({{xt|1-Naphthylamine is typically synthesized via the Feldenshlager{{ndash}}Glockenspiel process}}) although this can usually be avoided by rewording ({{xt|Feldenshlager{{ndash}}Glockenspiel is the process typically used in the synthesis of 1-naphthylamine}}).
 
:* Exception: Where a proper name, technical term, etc., itself beginning with a numeral, opens the sentence ({{xt|1-Naphthylamine is typically synthesized via the Feldenshlager{{ndash}}Glockenspiel process}}) although this can usually be avoided by rewording ({{xt|Feldenshlager{{ndash}}Glockenspiel is the process typically used in the synthesis of 1-naphthylamine}}).
 
{{shortcut|MOS:ORDINAL|WP:ORDINAL}}<!-- Positioned before (rather than after) section in question to avoid crash of shortcut boxes when sections are short. -->
 
  
 
===Ordinals===
 
===Ordinals===
  
* {{anchor|1st}}[[Ordinal indicator#English|Ordinal suffixes]] ({{xt|-st}}, {{xt|-nd}}, {{xt|-rd}}, {{xt|-th}}) are not [[superscript]]ed ({{xt|123rd}} and {{xt|496th}}, not {{!xt|123<sup>rd</sup>}} nor {{!xt|496<sup>th</sup>}}).
+
* [[Wikipedia:Ordinal indicator#English|Ordinal suffixes]] ({{xt|-st}}, {{xt|-nd}}, {{xt|-rd}}, {{xt|-th}}) are not [[Wikipedia:Superscript|superscripted]] ({{xt|123rd}} and {{xt|496th}}, not {{!xt|123<sup>rd</sup>}} nor {{!xt|496<sup>th</sup>}}).
 
* For guidance on choosing between e.g. {{xt|15th}} and {{xt|fifteenth}}, see {{section link||Numbers as figures or words}}.
 
* For guidance on choosing between e.g. {{xt|15th}} and {{xt|fifteenth}}, see {{section link||Numbers as figures or words}}.
* [[Regnal number]]s are normally written with [[Roman numeral]]s (without suffix, e.g. {{xt|Elizabeth II}} not {{!xt|Elizabeth IInd}}).
+
* [[Wikipedia:Regnal number|Regnal numbers]] are normally written with [[Wikipedia:Roman numeral|Roman numerals]] (without suffix, e.g. {{xt|Elizabeth II}} not {{!xt|Elizabeth IInd}}).
 
* Do not use a dot ({{!xt|.}}) or the ordinal mark ({{!xt|&#186;}}) to indicate ordinals.
 
* Do not use a dot ({{!xt|.}}) or the ordinal mark ({{!xt|&#186;}}) to indicate ordinals.
  
 
===Singular versus plural===
 
===Singular versus plural===
  
* Nouns following [[Simple fractions|simple fractions]] are singular ({{xt|He took {{frac|4}} dose}};{{nbsp}} {{xt|net change in score was &minus;{{frac|2}} point}};{{nbsp}} {{xt|{{frac|3|2}} dose}}).
+
* Nouns following [[Wikipedia:Simple fractions|simple fractions]] are singular ({{xt|He took <sup>1</sup>&frasl;<sub>4</sub> dose}};{{nbsp}} {{xt|net change in score was &minus;<sup>1</sup>&frasl;<sub>2</sub> point}};{{nbsp}} {{xt|<sup>3</sup>&frasl;<sub>2</sub> dose}}).
* Nouns following mixed numbers are plural ({{xt|suicide victim knew even 1{{frac|1|2}} doses could be fatal}};{{nbsp}} {{xt|continued another 4{{frac|3|4}} miles}}).
+
* Nouns following mixed numbers are plural ({{xt|suicide victim knew even 1<sup>1</sup>&frasl;<sub>2</sub> doses could be fatal}};{{nbsp}} {{xt|continued another 4<sup>3</sup>&frasl;<sub>4</sub> miles}}).
 
* Nouns following the lone, unsigned digit 1 are singular, but those following other decimal numbers (i.e. base-10 numbers not involving fractions) are plural ({{xt|increased 0.7 percentage points}};{{nbsp}} {{xt|365.25&nbsp;days}};{{nbsp}} {{xt|paid 5 dollars per work hour, 1 dollar per travel hour, 0 dollars per standby hour}};{{nbsp}} {{xt|increased by 1&nbsp;point}} but {{xt|net change +1&nbsp;points}};{{nbsp}} {{xt|net change &minus;1&nbsp;points}};{{nbsp}} {{xt|net change 1.0&nbsp;points}}).
 
* Nouns following the lone, unsigned digit 1 are singular, but those following other decimal numbers (i.e. base-10 numbers not involving fractions) are plural ({{xt|increased 0.7 percentage points}};{{nbsp}} {{xt|365.25&nbsp;days}};{{nbsp}} {{xt|paid 5 dollars per work hour, 1 dollar per travel hour, 0 dollars per standby hour}};{{nbsp}} {{xt|increased by 1&nbsp;point}} but {{xt|net change +1&nbsp;points}};{{nbsp}} {{xt|net change &minus;1&nbsp;points}};{{nbsp}} {{xt|net change 1.0&nbsp;points}}).
 
* The same rules apply to numbers given in words ({{xt|one dose}};{{nbsp}} {{xt|one and one-half doses}};{{nbsp}} {{xt|zero dollars}};{{nbsp}} {{xt|net change  negative one points}}).
 
* The same rules apply to numbers given in words ({{xt|one dose}};{{nbsp}} {{xt|one and one-half doses}};{{nbsp}} {{xt|zero dollars}};{{nbsp}} {{xt|net change  negative one points}}).
  
===<span id="Fractions"></span>Fractions and ratios===
+
===Fractions and ratios===
{{shortcut|MOS:FRAC|MOS:RATIO}}
+
 
 
* Spelled-out fractions are hyphenated: {{xt|seven-eighths}}.
 
* Spelled-out fractions are hyphenated: {{xt|seven-eighths}}.
* Where numerator and denominator can each be expressed in one word, a fraction is usually [[Fractions#Pronunciation and spelling|spelled out]] (e.g. {{xt|a two-thirds majority}}; {{nbsp}}{{xt|moved one-quarter mile}}); use figures if a fraction appears with a symbol (e.g. {{xt|{{frac|1|4}}{{nbsp}}mi}}{{snd}}markup: <code>{{tlx|frac|1|4}}&amp;nbsp;mi</code>, not {{!xt|a quarter of a mi}} or {{!xt|one-quarter mi}}).
+
* Where numerator and denominator can each be expressed in one word, a fraction is usually [[Wikipedia:Fractions#Pronunciation and spelling|spelled out]] (e.g. {{xt|a two-thirds majority}}; {{nbsp}}{{xt|moved one-quarter mile}}); use figures if a fraction appears with a symbol (e.g. {{xt|<sup>1</sup>&frasl;<sub>4</sub>{{nbsp}}mi}} - markup: <code><nowiki><sup>1</sup>&amp;frasl;<sub>4</sub>&amp;nbsp;mi</nowiki></code>, not {{!xt|a quarter of a mi}} or {{!xt|one-quarter mi}}).
* [[Mixed numbers]] are usually given in figures, unspaced (not {{!xt|Fellini's film ''8{{nbsp}}{{frac|1|2}}''}} or {{!xt|''8-{{frac|1|2}}''}} but {{xt|Fellini's film ''{{frac|8|1|2}}''}}{{snd}}markup:  <code><nowiki>{{frac|8|1|2}}</nowiki></code>). In any case the integer and fractional parts should be consistent (not {{!xt|nine and{{nbsp}}{{frac|1|2}}}}).
+
* [[Wikipedia:Mixed numbers|Mixed numbers]] are usually given in figures, unspaced (not {{!xt|Fellini's film ''8{{nbsp}}<sup>1</sup>&frasl;<sub>2</sub>''}} or {{!xt|''8-<sup>1</sup>&frasl;<sub>2</sub>''}} but {{xt|Fellini's film ''8<sup>1</sup>&frasl;<sub>2</sub>''}} - markup:  <code><nowiki>8<sup>1</sup>&amp;frasl;<sub>2</sub></nowiki></code>). In any case the integer and fractional parts should be consistent (not {{!xt|nine and{{nbsp}}<sup>1</sup>&frasl;<sub>2</sub>}}).
* Metric (SI) measurements generally use decimals, not fractions ({{xt|5.25{{nbsp}}mm}}, not {{!xt|5{{frac|1|4}}{{nbsp}}mm}}).
+
* Metric (SI) measurements generally use decimals, not fractions ({{xt|5.25{{nbsp}}mm}}, not {{!xt|5<sup>1</sup>&frasl;<sub>4</sub>{{nbsp}}mm}}).
* Non-metric (imperial and US customary) measurements may use fractions or decimals ({{xt|5{{frac|1|4}}{{nbsp}}inches}};{{nbsp}}{{xt|5.25{{nbsp}}inches}}); the practice of reliable sources should be followed, and within-article consistency is desirable.
 
* In science and mathematics articles mixed numbers are rarely used (not {{!xt|1{{frac|1|3}} times the original voltage}}, but {{xt|4/3 the original}}) and use of {{tlx|frac}} is discouraged in favor of one of these styles:
 
: &nbsp; &bull; &nbsp; <math>\textstyle\frac{1}{2}</math>{{snd}}markup: <code><[[WP:MATH|math]]>\textstyle\frac{1}{2}<nowiki></math></nowiki></code>
 
: &nbsp; &bull; &nbsp; {{xt|{{sfrac|1|2}}}}{{snd}}markup: {{tlx|sfrac|1|2}}
 
: &nbsp; &bull; &nbsp; {{xt|1/2}}{{snd}}markup: <code>1/2</code>
 
 
* Do not use special characters such as "&frac12;" (deprecated markup: <s><code>&amp;frac12;</code></s> or <s><code>&amp;#189;</code></s>).   
 
* Do not use special characters such as "&frac12;" (deprecated markup: <s><code>&amp;frac12;</code></s> or <s><code>&amp;#189;</code></s>).   
* Ordinal suffixes such as {{xtn|-th}} should not be used with fractions expressed in figures (not {{!xt|each US state has 1/50th of the [[United States Senate|Senate's]] votes}};&nbsp; {{!xt|1/8th mile}}, but {{xt|one-fiftieth of the [[United States Senate|Senate's]] votes}};&nbsp; {{xt|1/8 mile}};&nbsp; {{xt|one-eighth mile}}).
+
* Ordinal suffixes such as '''-th''' should not be used with fractions expressed in figures (not {{!xt|each US state has 1/50th of the [[Wikipedia:United States Senate|Senate's]] votes}};&nbsp; {{!xt|1/8th mile}}, but {{xt|one-fiftieth of the [[Wikipedia:United States Senate|Senate's]] votes}};&nbsp; {{xt|1/8 mile}};&nbsp; {{xt|one-eighth mile}}).
*Dimensionless ratios (i.e. those not incorporating units) are given using numerals and a colon, or numbers-as-words and ''to'': {{ xt|favored by a 3:1 ratio}} or {{nobr|{{ xt|a three-to-one ratio}},}} but not {{nobr|{{!xt|a 3/1 ratio}}}} or {{nobr|{{!xt|a 3&ndash;1 ratio}}.}} Use a "spaced" colon when a decimal point is present {{nobr|({{ xt|a 3.5&nbsp;:&nbsp;1 ratio}}{{snd}}markup:}} {{nobr|<code>a 3.5&amp;nbsp;:&amp;nbsp;1 ratio</code>).}} Do not use the colon form where units are involved ({{!xt|dissolve using a {{nobr|3 ml:1 g ratio}}}}){{mdashb}}instead see ''ratios'' section of table at [[#Unit names and symbols|§&nbsp;Unit names and symbols]], below.''
+
* Dimensionless ratios (i.e. those not incorporating units) are given using numerals and a colon, or numbers-as-words and ''to'': {{xt|favored by a 3:1 ratio}} or {{xt|a three-to-one ratio}}, but not {{!xt|a 3/1 ratio}} or {{!xt|a 3&ndash;1 ratio}}. Use a "spaced" colon when a decimal point is present ({{xt|a 3.5&nbsp;:&nbsp;1 ratio}} - markup: <code>a 3.5&amp;nbsp;:&amp;nbsp;1 ratio</code>). Do not use the colon form where units are involved ({{!xt|dissolve using a 3 ml:1 g ratio}})&mdash;instead see ''ratios'' section of table at [[#Unit names and symbols|§&nbsp;Unit names and symbols]], below.''
 +
 
 +
===Decimals===
 +
 
 +
* A period/full point (<code>.</code>), ''never'' a comma, is used as the decimal point ({{xt|6.57}}, not {{!xt|6,57}}).
 +
* Numbers between −1 and +1 require a leading zero ({{xt|0.02}}, not {{!xt|.02}}); exceptions are sporting performance averages ({{xt|.430 [[Wikipedia:Batting average|batting average]]}}) and commonly used terms such as {{xt|.22{{nbsp}}caliber}}.
 +
* Indicate repeating digits with an [[Wikipedia:Vinculum (symbol)|overbar]] e.g. <code><nowiki>14.31<span style="text-decoration:overline">28</span></nowiki></code> gives <span style="color:green">14.31<span style="text-decoration:overline">28</span></span>. (Consider explaining this notation on first use.) Do not write e.g. {{!xt|14.31(28)}} because it resembles notations for {{section link||Uncertainty and rounding}}.
  
===<span id="Decimal points"></span>Decimals===
+
====Grouping
{{shortcut|WP:DECIMAL|MOS:DECIMAL}}
+
of digits====
* A period/full point (<code>.</code>), {{em|never}} a comma, is used as the decimal point ({{xt|6.57}}, not {{!xt|6,57}}).
 
* Numbers between −1 and +1 require a leading zero ({{xt|0.02}}, not {{!xt|.02}}); exceptions are sporting performance averages ({{xt|.430 [[batting average]]}}) and commonly used terms such as {{xt|.22{{nbsp}}caliber}}.
 
* Indicate repeating digits with an [[Vinculum (symbol)|overbar]] e.g. {{nowrap|<code><nowiki>14.31{{overline|28}}</nowiki></code>}} gives {{xt|14.31{{overline|28}}}}. (Consider explaining this notation on first use.) Do not write e.g. {{nobr|{{!xt|14.31(28)}}}} because it resembles notations for {{section link||Uncertainty}}.
 
  
====<span id="Delimiting (grouping of digits)"></span>Grouping of digits====
+
* Digits should be grouped and separated by commas, (''never'' a period/full point).
{{shortcut|WP:DIGITS|MOS:DIGITS}}
 
* Digits should be grouped and separated either by commas or narrow gaps ({{em|never}} a period/full point).
 
 
:; Grouping with commas
 
:; Grouping with commas
:* Left of the decimal point, five or more digits are grouped into threes separated by commas (e.g. &nbsp;{{xt|12,200}}, &nbsp;{{xt|255,200&nbsp;km}}, &nbsp;{{xt|8,274,527th}}, &nbsp;{{xt|{{frac|86,400}}}}).
+
:* Left of the decimal point, five or more digits are grouped into threes separated by commas (e.g. &nbsp;{{xt|12,200}}, &nbsp;{{xt|255,200&nbsp;km}}, &nbsp;{{xt|8,274,527th}}, &nbsp;{{xt|<sup>1</sup>&frasl;<sub>86,400</sub>}}).
 
:* Numbers with exactly four digits left of the decimal point may optionally be grouped (either &nbsp;{{xt|1,250}} &nbsp;or &nbsp;{{xt|1250}}), provided that this is consistent within each article.
 
:* Numbers with exactly four digits left of the decimal point may optionally be grouped (either &nbsp;{{xt|1,250}} &nbsp;or &nbsp;{{xt|1250}}), provided that this is consistent within each article.
 
:* When commas are used left of the decimal point, digits right of the decimal point are not grouped (i.e. should be given as an unbroken string).
 
:* When commas are used left of the decimal point, digits right of the decimal point are not grouped (i.e. should be given as an unbroken string).
:* Markup: {{tlc|[[Help:Parser functions|formatnum:]]}} produces this formatting.
 
:; Grouping with narrow gaps
 
:* Digits are grouped both sides of the decimal point (e.g. &nbsp;{{xt|{{val|6543210.123456}}}}, &nbsp;{{xt|{{val|520.01234|u=degC}}}}, &nbsp;{{xt|{{sfrac|{{val|101325}}|760}}}}).
 
:* Digits are generally grouped into threes. Right of the decimal point, {{em|usual}} practice is to have a final group of four instead of a lone digit (e.g. &nbsp;{{xt|{{val|99.1234567}}}} &nbsp;or &nbsp;{{xt|{{gaps|99.123|456|7}}}}). In mathematics-oriented articles long strings may be grouped into fives (e.g. &nbsp;{{xt|{{gaps|3.14159|26535|89793|23846|...}}}}).
 
:* This style is especially recommended for articles related to science, technology, engineering or mathematics.
 
:* Markup: Templates {{tlx|val}} or {{tlx|gaps}} may be used to produce this formatting. Note that use of {{em|any}} space character in numbers, including non-breaking space, is problematic for [[screen reader]]s. {{crossref|(See [[#Non-breaking spaces|&sect;Non-breaking spaces]].)}}  Screen readers read out each {{em|group}} of digits as separate numbers (e.g. &nbsp;<code>30&amp;thinsp;000</code>&nbsp; is read as "thirty zero zero zero".)
 
 
* Delimiting style should be consistent throughout a given article.
 
* Delimiting style should be consistent throughout a given article.
:* Either use commas or narrow gaps, but not both in the same article.
 
 
:* Either group the thousands in a four-digit number or do not, but not mixed use in the same article.
 
:* Either group the thousands in a four-digit number or do not, but not mixed use in the same article.
 
:* However, grouping by threes and fives may coexist.
 
:* However, grouping by threes and fives may coexist.
* An exception is made for four-digit page numbers or four-digit calendar years.  These should never be grouped (not &nbsp;{{!xt|sailed in 1,492}}, &nbsp;though &nbsp;{{xt|dynasty collapsed around 10,400&nbsp;BC}} &nbsp;or &nbsp;{{xt|by {{val|13727|u=AD}}, Vega will be the northern pole star}}).
+
* An exception is made for four-digit page numbers or four-digit calendar years.  These should never be grouped (not &nbsp;{{!xt|sailed in 1,492}}, &nbsp;though &nbsp;{{xt|dynasty collapsed around 10,400&nbsp;BC}}).
  
 
===Percentages===
 
===Percentages===
{{shortcut|MOS:PERCENT|WP:PERCENT|WP:%}}
 
* In the body of non-scientific/non-technical articles, {{xtn|percent}} (American English) or {{xtn|per cent}} (British English) are commonly used: {{xt|10 percent}}; {{xt|ten percent}}; {{xt|4.5 per cent}}. Ranges are written {{xt|ten to twelve per cent}} or {{xt|ten to twelve percent}}, not {{!xt|ten{{ndash}}twelve per cent}} or {{!xt|ten to twelve{{nbsp}}%}}.
 
* In the body of scientific/{{zwsp}}technical articles, and in {{em|tables and infoboxes}} of any article, the symbol <code>%</code> (unspaced) is more common: {{xt|71%}}, not {{!xt|71 %}} or {{!xt|three %}}. Ranges: {{xt|10{{ndash}}12%}}, not {{!xt|10%{{ndash}}12%}} or {{nobr|{{!xt|10 to 12%}}}}.
 
* When expressing the difference between two percentages, do not confuse a percentage change with a change in [[percentage point]]s.
 
  
===<span id="Scientific notation, engineering notation, and uncertainty"></span>Scientific and engineering notation===
+
* In the body of non-scientific/non-technical articles, '''percent''' (American English) or '''per cent''' (British English) are commonly used: {{xt|10 percent}}; {{xt|ten percent}}; {{xt|4.5 per cent}}. Ranges are written {{xt|ten to twelve per cent}} or {{xt|ten to twelve percent}}, not {{!xt|ten{{ndash}}twelve per cent}} or {{!xt|ten to twelve{{nbsp}}%}}.
* [[Scientific notation]] always has a single nonzero digit to the left of the point: not {{!xt|{{val|60.22|e=22}}}}, but {{xt|{{val|6.022|e=23}}}}.  
+
* In the body of scientific/{{zwsp}}technical articles, and in ''tables and infoboxes'' of any article, the symbol <code>%</code> (unspaced) is more common: {{xt|71%}}, not {{!xt|71 %}} or {{!xt|three %}}. Ranges: {{xt|10{{ndash}}12%}}, not {{!xt|10%{{ndash}}12%}} or {{!xt|10 to 12%}}.
* [[Engineering notation]] is similar, but adjusted so that the exponent is a multiple of three: {{xt|{{val|602.2|e=21}}}}.
+
* When expressing the difference between two percentages, do not confuse a percentage change with a change in [[Wikipedia:Percentage point|percentage points]].
* Avoid mixing scientific and engineering notations ({{!xt|A {{val|2.23|e=2|u=m2}} region covered by {{val|234.0|e=6|u=grains of sand}}}}).  
+
 
* In a table column (or other presentation) in which all values can be expressed with a single power of 10, consider giving e.g. {{xt|{{e|7}}}} once in the column header, and omitting it in the individual entries. (Markup: <code><nowiki>{{e|7}}</nowiki></code>)
+
===Scientific notation===
* In both notations, the number of digits indicates the precision. For example, {{xt|{{val|5|e=3}}}} means rounded to the nearest thousand; {{xt|{{val|5.0|e=3}}}} to the nearest hundred; {{xt|{{val|5.00|e=3}}}} to the nearest ten; and {{xt|{{val|5.000|e=3}}}} to the nearest unit.
+
* [[Wikipedia:Scientific notation|Scientific notation]] always has a single nonzero digit to the left of the point: not {{!xt|60.22&nbsp;&times;&nbsp;10<sup>22</sup>}}, but {{xt|6.022&nbsp;&times;&nbsp;10<sup>23</sup>}}.  
 +
* In a table column (or other presentation) in which all values can be expressed with a single power of 10, consider giving e.g. {{xt|&nbsp;&times;&nbsp;10<sup>7</sup>}} once in the column header, and omitting it in the individual entries. (Markup: <code><nowiki>&amp;nbsp;&amp;times;&amp;nbsp;10<sup>7</sup></nowiki></code>)
 +
* The number of digits indicates the precision. For example, {{xt|5&nbsp;&times;&nbsp;10<sup>3</sup>}} means rounded to the nearest thousand; {{xt|5.0&nbsp;&times;&nbsp;10<sup>3</sup>}} to the nearest hundred; {{xt|5.00&nbsp;&times;&nbsp;10<sup>3</sup>}} to the nearest ten; and {{xt|5.000&nbsp;&times;&nbsp;10<sup>3</sup>}} to the nearest unit.
  
Markup: {{tlx|val}} and {{tlx|e}} may be used to format exponential notation.
+
===Uncertainty and rounding===
  
===Uncertainty and rounding <span id="Uncertainty"></span> <span id="Large numbers"></span>===
+
* Where explicit uncertainty information (such as a [[Wikipedia:Margin of error|margin of error]]) is available and appropriate for inclusion, it may be written in various ways:
{{shortcut|MOS:UNCERTAINTY|MOS:LARGENUM}}
 
* Where explicit uncertainty information (such as a [[margin of error]]) is available and appropriate for inclusion, it may be written in various ways:
 
 
: &nbsp; &bull; &nbsp;{{xt|(1.534 ± 0.035) × 10<sup>23</sup> m}}  
 
: &nbsp; &bull; &nbsp;{{xt|(1.534 ± 0.035) × 10<sup>23</sup> m}}  
 
: &nbsp; &bull; &nbsp;{{xt|12.34{{nbsp}}m<sup>2</sup> ± 5%}} (not used with scientific notation)
 
: &nbsp; &bull; &nbsp;{{xt|12.34{{nbsp}}m<sup>2</sup> ± 5%}} (not used with scientific notation)
: &nbsp; &bull; &nbsp;{{xt|15.34 {{su|p=+0.43|b=−0.23}} × 10<sup>23</sup> m}}
+
: &nbsp; &bull; &nbsp;{{xt|1.604(48) × 10<sup>−4</sup> J}} (equivalent to {{xt|(1.604 ± 0.048) × 10<sup>−4</sup> J}})<ref>The number in parentheses is the numerical value of the standard uncertainty referred to the corresponding last digits of the quoted result – see [http://www.physics.nist.gov/cgi-bin/cuu/Info/Constants/definitions.html NIST – Use of concise notation]</ref>
: &nbsp; &bull; &nbsp;{{xt|1.604(48) × 10<sup>−4</sup> J}} (equivalent to {{xt|(1.604 ± 0.048) × 10<sup>−4</sup> J}})<ref>The number in parentheses is the numerical value of the standard uncertainty referred to the corresponding last digits of the quoted result – {{crossref|see [http://www.physics.nist.gov/cgi-bin/cuu/Info/Constants/definitions.html NIST – Use of concise notation]}}</ref>
 
 
: &nbsp; &bull; &nbsp;{{xt|Polls estimated Jones's share of the vote would be 55 percent, give or take about 3 percent}}
 
: &nbsp; &bull; &nbsp;{{xt|Polls estimated Jones's share of the vote would be 55 percent, give or take about 3 percent}}
:Markup: {{tlx|+-}}, {{tlx|su}}, and {{tlx|val}} may be used to format uncertainties.
+
* Where explicit ''uncertainty is unavailable'' (or is unimportant for the article's purposes) round to an appropriate number of [[Wikipedia:Significant digit|significant digits]]; the precision presented should usually be conservative. Precise values (often given in sources for formal or matter-of-record reasons) should be used only where stable and appropriate to the context, or significant in themselves for some special reason.
* Where explicit {{em|uncertainty is unavailable}} (or is unimportant for the article's purposes) round to an appropriate number of [[significant digit]]s; the precision presented should usually be conservative. Precise values (often given in sources for formal or matter-of-record reasons) should be used only where stable and appropriate to the context, or significant in themselves for some special reason.
 
 
: &nbsp; &bull; &nbsp; {{xt|The speed of light is defined to be 299,792,458{{nbsp}}m/s}}
 
: &nbsp; &bull; &nbsp; {{xt|The speed of light is defined to be 299,792,458{{nbsp}}m/s}}
:: {{em|but}} {{xt|Particle velocities eventually reached almost two-thirds the 300-million-metre-per-second speed of light.}}
+
:: ''but'' {{xt|Particle velocities eventually reached almost two-thirds the 300-million-metre-per-second speed of light.}}
: &nbsp; &bull; &nbsp; {{xt|The city's 1920 population was 10,000}} (not {{!xt|population was 9,996}}{{snd}}an official figure unlikely to be accurate at full precision)
+
: &nbsp; &bull; &nbsp; {{xt|The city's 1920 population was 10,000}} (not {{!xt|population was 9,996}} - an official figure unlikely to be accurate at full precision)
:: {{em|but}} {{xt|The town was ineligible because its official census figure (9,996) fell short of the statutory minimum of ten thousand }} (unusual case in which the full-precision official population figure is helpful to readers)
+
:: ''but'' {{xt|The town was ineligible because its official census figure (9,996) fell short of the statutory minimum of ten thousand }} (unusual case in which the full-precision official population figure is helpful to readers)
 
: &nbsp; &bull; &nbsp; {{xt| The accident killed 337 passengers and crew, and three airport workers }} (likely that accurate and precise figures were determined)
 
: &nbsp; &bull; &nbsp; {{xt| The accident killed 337 passengers and crew, and three airport workers }} (likely that accurate and precise figures were determined)
 
: &nbsp; &bull; &nbsp; {{xt| At least 800 persons died in the ensuing mudslides }} (unlikely that any precise number can be accurate, even if an official figure is issued)
 
: &nbsp; &bull; &nbsp; {{xt| At least 800 persons died in the ensuing mudslides }} (unlikely that any precise number can be accurate, even if an official figure is issued)
:: {{em|or}} {{xt| Officials listed 835 deaths, but the Red Cross said dozens more may have gone unreported }} (in reporting conflicting information, give detail sufficient to make the contrast intelligible)
+
:: ''or'' {{xt| Officials listed 835 deaths, but the Red Cross said dozens more may have gone unreported }} (in reporting conflicting information, give detail sufficient to make the contrast intelligible)
: &nbsp; &bull; &nbsp; {{xt|The jury's award was $8.5{{nbsp}}million{{nbsp}}...}} (where the actual figure was $8,462,247.63) {{xt| ...{{snd}}reduced on appeal to $3,000,001 (one dollar in [[actual damages]], the remainder in [[punitive damages]])}}
+
: &nbsp; &bull; &nbsp; {{xt|The jury's award was $8.5{{nbsp}}million{{nbsp}}...}} (where the actual figure was $8,462,247.63) {{xt| ... - reduced on appeal to $3,000,001 (one dollar in [[Wikipedia:Actual damages|actual damages]], the remainder in [[Wikipedia:Punitive damages|punitive damages]])}}
 
* The number of decimal places should be consistent within a list or context ({{xt|The response rates were 41.0 and 47.4 percent, respectively}}, not {{!xt|41 and 47.4 percent}}), unless different precisions are actually intended.
 
* The number of decimal places should be consistent within a list or context ({{xt|The response rates were 41.0 and 47.4 percent, respectively}}, not {{!xt|41 and 47.4 percent}}), unless different precisions are actually intended.
* It may sometimes be appropriate to note the {{em|lack}} of uncertainty information, especially where such information is normally provided and necessary for full interpretation of the figures supplied.
+
* It may sometimes be appropriate to note the ''lack'' of uncertainty information, especially where such information is normally provided and necessary for full interpretation of the figures supplied.
 
: &nbsp; &bull; &nbsp; {{xt|A local newspaper poll predicted 52 percent of the vote would go to Smith, but did not publish information on the uncertainty of this estimate}}
 
: &nbsp; &bull; &nbsp; {{xt|A local newspaper poll predicted 52 percent of the vote would go to Smith, but did not publish information on the uncertainty of this estimate}}
* The {{tlx|undue precision}} template may be added to figures appearing to be overprecise.
 
  
 
* Avoid using "approximately", "about", and similar terms with figures that have merely been approximated or rounded in a normal and expected way, unless the reader might otherwise be misled.
 
* Avoid using "approximately", "about", and similar terms with figures that have merely been approximated or rounded in a normal and expected way, unless the reader might otherwise be misled.
: &nbsp; &bull; &nbsp; {{xt|The tallest player was 6 feet 3 inches}} ({{nobr|not {{!xt|... about 6 feet 3 inches}}}}{{snd}}heights are conventionally reported only to the nearest inch, even though greater precision may be available in principle)<!-- Please, no lectures about SI – if you can give a parallel metric example please do so. -->
+
: &nbsp; &bull; &nbsp; {{xt|The tallest player was 6 feet 3 inches}} (not {{!xt|... about 6 feet 3 inches}} - heights are conventionally reported only to the nearest inch, even though greater precision may be available in principle)
:: {{em|but}} {{xt|The witness said the assailant was about 5 feet 8 inches tall}} ("about" because here the precise value is unknown, with substantial uncertainty)
+
:: ''but'' {{xt|The witness said the assailant was about 5 feet 8 inches tall}} ("about" because here the precise value is unknown, with substantial uncertainty)
 
* The reader may be assumed to interpret large round numbers ({{xt|100,000 troops}}) as approximations. Writing a quantity in words ({{xt|one hundred thousand troops}}) can further emphasize its approximate nature.
 
* The reader may be assumed to interpret large round numbers ({{xt|100,000 troops}}) as approximations. Writing a quantity in words ({{xt|one hundred thousand troops}}) can further emphasize its approximate nature.
  
* {{crossref|See {{section link||Unit conversions}} below for precision issues when converting units.}}
+
===Non-[[Wikipedia:radix|base]]-10 notations===
  
===Non-[[radix|base]]-10 notations===
+
* In computer-related articles, use the prefix <code>0x</code> for hexadecimal, <code>0</code> for octal, and  <code>0b</code> for binary, unless there is a strong reason to use some other notation.<ref>The <code>0x</code> and <code>0</code> prefixes, but not <code>0b</code>, are borrowed from the [[Wikipedia:C (programming language)|C programming language]].</ref> Explain these prefixes in the article's introduction or on first use.
{{shortcut|MOS:BASE|MOS:RADIX|MOS:BINARY|MOS:HEX}}
 
* In computer-related articles, use the prefix <code>0x</code> for hexadecimal, <code>0</code> for octal, and  <code>0b</code> for binary, unless there is a strong reason to use some other notation.<ref>The <code>0x</code> and <code>0</code> prefixes, but not <code>0b</code>, are borrowed from the [[C (programming language)|C programming language]].</ref> Explain these prefixes in the article's introduction or on first use.
 
 
* In all other articles, use <code>&lt;sub></code> to create subscripts: {{xt|137<sub>9</sub>}}, {{xt|201<sub>3</sub>}}. Markup: {{xt|137<nowiki><sub>9</sub></nowiki>}}, {{xt|201<nowiki><sub>3</sub></nowiki>}}
 
* In all other articles, use <code>&lt;sub></code> to create subscripts: {{xt|137<sub>9</sub>}}, {{xt|201<sub>3</sub>}}. Markup: {{xt|137<nowiki><sub>9</sub></nowiki>}}, {{xt|201<nowiki><sub>3</sub></nowiki>}}
* For bases above 10, use symbols conventional for that base (as seen in reliable sources) e.g. for [[base 16]] use {{nobr|0{{ndash}}9 and A{{ndash}}F}}.
+
* For bases above 10, use symbols conventional for that base (e.g. for [[Wikipedia:Base 16|base 16]] use 0{{ndash}}9 and A{{ndash}}F.
  
 
==Units of measurement==
 
==Units of measurement==
{{Shortcut|WP:UNIT|WP:UNITS|WP:METRIC|WP:MEASUREMENT}}
 
  
 
===Unit choice and order===
 
===Unit choice and order===
  
Quantities are typically expressed using an appropriate "primary unit", displayed first, followed, when appropriate, by a conversion in parentheses e.g. {{xt|{{convert|200|km|mi}}}}. For details on when and how to provide a conversion, see the section {{section link||Unit conversions}}. The choice of primary units depends on the circumstances, and should respect the principle of "[[Wikipedia:Strong national ties|strong national ties]]", where applicable:
+
Quantities are typically expressed using an appropriate "primary unit", displayed first, followed, when appropriate, by a conversion in parentheses e.g. {{xt|200 kilometers (120 mi)}}.
 
 
* In '''non-scientific articles relating to the United States''', the primary units are [[United States customary units|US customary]], e.g. {{xt|97{{nbsp}}pounds (44{{nbsp}}kg)}}.
 
* In '''non-scientific articles relating to the United Kingdom''', the primary units for most quantities are metric or other internationally used units,<ref name="UKmetricUnits">If there is disagreement about the primary units used in a UK-related article, discuss the matter on the article talk-page, at [[WT:MOSNUM|MOSNUM talk]], or both. If consensus cannot be reached, refer to historically stable versions of the article and retain the units used in these as the primary units. Also note the [[Metrication in the UK#Newspapers|style guides]] of British publications such as ''The Times'' (see [https://web.archive.org/web/20110918050646/http://www.timesonline.co.uk/tol/tools_and_services/specials/style_guide/article986731.ece archived version], under "Metric").</ref> except that:
 
** UK engineering-related articles, including those on bridges and tunnels, generally use the system of units that the topic was [[engineering drawing|drawn up]] in (but road distances are given in imperial units, with a metric conversion – see next bullet);
 
** the primary units for distance/{{zwsp}}length, speed and fuel consumption are miles, miles per hour, and miles per imperial gallon (except for short distances or lengths, where miles are too large for practical use);
 
** the primary units for personal height and weight are feet{{zwsp}}/inches and stones/{{zwsp}}pounds;
 
** imperial pints are used for quantities of draught beer/{{zwsp}}cider and bottled milk;
 
* In '''all other articles''', the primary units chosen will be [[International System of Units|SI]] units, [[Non-SI units mentioned in the SI|non-SI units officially accepted for use with the SI]], or such other units as are conventional in reliable-source discussions of the article topic (such as [[revolutions per minute]] (rpm) for angular speed, [[hand (unit)|hand]]s for heights of horses, et cetera).
 
  
{{em|Special considerations:}}
+
In '''all articles''', the primary units chosen will be [[Wikipedia:International System of Units|SI]] units, [[Wikipedia:Non-SI units mentioned in the SI|non-SI units officially accepted for use with the SI]], or such other units as they appear in-game.
* Quantities set via definition (as opposed to measured quantities) should be given first in the units used in the definition, even if this makes the structure of presentation inconsistent: {{xt|During metrification, the speed limit was changed from 30{{nbsp}}mph (48{{nbsp}}km/h) to 50{{nbsp}}km/h (31{{nbsp}}mph)}}.
 
** Or use ''about'' to emphasize which is the statutory, exact value: {{xt|...from 30{{nbsp}}mph (about 48{{nbsp}}km/h) to 50{{nbsp}}km/h (about 31{{nbsp}}mph)}}.
 
* Nominal quantities (e.g. {{xt|{{nowrap|[[2x4 (disambiguation)|2 &times; 4]]}} lumber}}) require consideration of whether the article is concerned with the item's actual dimensions or merely with its function. In some cases only the nominal quantity may suffice; in others it may be necessary to give the nominal size (often in non-SI units), the actual size in non-SI units, and the actual size in SI units.
 
* Whenever a conversion is used, ensure that the precision of the converted quantity in the article is comparable to the precision of the value given by the source {{crossref|(see {{section link||Unit conversions}})}}.
 
* Where the article's primary units differ from the units given in the source, the {{tlx|convert}} template's <code>|order=flip</code> flag can be used; this causes the {{em|original}} unit to be shown as secondary in the article, and the {{em|converted}} unit to be shown as primary: <code><nowiki>{{convert|200|mi|km|order=flip}}</nowiki></code> &rarr; {{xt|The two cities are {{convert|200|mi|km|order=flip}} apart.}}
 
 
 
===Unit conversions===
 
{{shortcut|MOS:CONVERSIONS|WP:MOSCONVERSIONS}}
 
Where English-speaking countries use different units for the same quantity, provide a conversion in parentheses: {{xt|the Mississippi River is {{convert|2320|mi|km|0}} long}}; {{xt|the Murray River is {{convert|2508|km|mi|0}} long}}. In science-related articles, however, supplying such conversion is not required unless there is some special reason to do so.
 
* Where an [[imperial unit]] is not part of the [[United States customary units|US customary system]], or vice-versa{{snd}}and in particular, where those systems give a single term different definitions{{snd}}a double conversion may be appropriate: {{xt|Rosie weighed {{convert|80|kg|lb stlb}}}} (markup: <code><nowiki>{{convert|80|kg|lb stlb}}</nowiki></code>); {{xt|{{nobr|The car}} had a fuel economy of {{convert|5|L/100km|mpgus mpgimp|abbr=on}}}} (markup: <code><nowiki>{{convert|5|L/100km|mpgus mpgimp|abbr=on}}</nowiki></code>).
 
* Generally, conversions to and from metric units and US or imperial units should be provided, except:
 
** When inserting a conversion would make a common or linked expression awkward ({{xt|The four-minute mile}}).
 
** When units are part of the subject of a topic{{snd}}nautical miles in articles about the history of nautical law ({{xt|5 nautical miles}}), [[International System of Units|SI]] units in scientific articles ({{xt|a 600-kilometer asteroid}}), yards in articles about American football{{snd}}it can be excessive to provide conversions every time a unit occurs. It might be best to note that this topic will use the units (possibly giving the conversion factor to another familiar unit in a parenthetical note or a footnote), and link the first occurrence of each unit but not give a conversion every time it occurs.
 
* Converted quantity values should use a {{em|level of precision}} similar to that of the source quantity value, so {{xt|the Moon is 380,000{{nbsp}}kilometres (240,000{{nbsp}}mi) from Earth}}, not {{!xt|(236,121{{nbsp}}mi)}}. Small numbers may need to be converted to a range where rounding would cause a significant distortion, so {{xt|one mile (1–2{{nbsp}}km)}}, not {{!xt|one mile (2{{nbsp}}km)}}.  Be careful especially when your source has already converted from the units you're now converting back to.  This may be evidenced by multiples of common conversion factors in the data, such as 160 km (from 100 miles). {{crossref|See [[false precision]].}}
 
* [[:Category:Conversion templates|'''Conversion templates''']] can be used to convert and format many common units, including {{tlx|convert}}, which includes non-breaking spaces.
 
* In a '''direct quotation''', always retain the source units. Any conversions can be supplied either in the quote itself (in square brackets, following the original measurement) or in a footnote. {{crossref|See [[Wikipedia:Footnotes|footnoting]] and [[Wikipedia:Citing sources|citing sources]].}}
 
* {{tlx|Units attention}} may be added to articles needing general attention regarding choice of units and unit conversions.
 
  
 
===Unit names and symbols===
 
===Unit names and symbols===
:{{em|Definitions:}}
+
:''Definitions:''
 
:* Examples of '''unit names''': foot, meter, kilometer.
 
:* Examples of '''unit names''': foot, meter, kilometer.
 
:* Examples of '''unit symbols''': ft, m, km.
 
:* Examples of '''unit symbols''': ft, m, km.
Line 466: Line 352:
 
* In prose, unit names should be given in full if used only a few times, but symbols may be used when a unit (especially one with a long name) is used repeatedly, after spelling out the first use (e.g. {{xt|Up to 15 kilograms of filler is used for a batch of 250{{nbsp}}kg}}).
 
* In prose, unit names should be given in full if used only a few times, but symbols may be used when a unit (especially one with a long name) is used repeatedly, after spelling out the first use (e.g. {{xt|Up to 15 kilograms of filler is used for a batch of 250{{nbsp}}kg}}).
 
:* Exception: Certain units<!--<<perhaps identify these in table of specific units elsewhere on this page--> are generally represented by their symbols (e.g. {{xt|&deg;C}} rather than {{!xt|degrees Celsius}}) even on first use, though their unit names may be used for emphasis or clarity ({{xt|automatic conversion of degrees Celsius to degrees Fahrenheit}}).
 
:* Exception: Certain units<!--<<perhaps identify these in table of specific units elsewhere on this page--> are generally represented by their symbols (e.g. {{xt|&deg;C}} rather than {{!xt|degrees Celsius}}) even on first use, though their unit names may be used for emphasis or clarity ({{xt|automatic conversion of degrees Celsius to degrees Fahrenheit}}).
:* Exception: Consider using ''inches'' (but not ''in.'') in place of ''in'' where the latter might be misread as a preposition<!--can someone supply an example? (if no one can think of one after a while, then maybe this exception never actually arises)-->{{mdashb}}but not where the value is followed by a parenthesized conversion e.g. {{xt|bolts 5&nbsp;in (12.7&nbsp;cm) long}}, or is part of such a conversion ({{xt|bolts 12.7&nbsp;cm (5&nbsp;in) long}}).
 
 
* Where space is limited, such as in tables, infoboxes, parenthetical notes, and mathematical formulas, unit symbols are preferred.
 
* Where space is limited, such as in tables, infoboxes, parenthetical notes, and mathematical formulas, unit symbols are preferred.
* Units unfamiliar to general readers should be presented as a name{{ndash}}symbol pair on first use, linking the unit name ({{xt|Energies were originally 2.3 [[megaelectronvolt]]s (MeV), but were eventually 6{{nbsp}}MeV}}).
+
* Units unfamiliar to general readers should be presented as a name{{ndash}}symbol pair on first use, linking the unit name ({{xt|Energies were originally 2.3 [[Wikipedia:Megaelectronvolts|megaelectronvolts]] (MeV), but were eventually 6{{nbsp}}MeV}}).
* Ranges use unspaced en dash ({{tlx|ndash}}) if only one unit symbol is used at the end (e.g. {{xt|5.9{{ndash}}6.3{{nbsp}}kg}}), and spaced en dash ({{tlx|snd}}) if two symbols are used (e.g. {{xt|3{{nbsp}}μm{{snd}}1{{nbsp}}mm}}); ranges in prose may be specified using either unit symbol or unit names, and units may be stated either after both numerical values or after the last (e.g. {{nobr|{{xt|from 5.9 to 6.3 kilograms}}}}, {{nobr|{{xt|from 5.9 kilograms to 6.3 kilograms}}}}, {{nobr|{{xt|from 5.9 to 6.3{{nbsp}}kg}}}} and {{nobr|{{xt|from 5.9{{nbsp}}kg to 6.3{{nbsp}}kg}}}} are all acceptable).
+
* Ranges use unspaced en dash ({{tl|ndash}}) if only one unit symbol is used at the end (e.g. {{xt|5.9{{ndash}}6.3{{nbsp}}kg}}), and spaced en dash ({{tl|snd}}) if two symbols are used (e.g. {{xt|3{{nbsp}}μm - 1{{nbsp}}mm}}); ranges
* Length{{ndash}}width, length{{ndash}}width{{ndash}}height and similar dimensions may be separated by the multiplication sign (<code>×</code> or <code>&amp;times;</code>) or the word {{xtn|by}}.
+
in prose may be specified using either unit symbol or unit names, and units may be stated either after both numerical values or after the last (e.g. {{xt|from 5.9 to 6.3 kilograms}}, {{xt|from 5.9 kilograms to 6.3 kilograms}}, {{xt|from 5.9 to 6.3{{nbsp}}kg}} and {{xt|from 5.9{{nbsp}}kg to 6.3{{nbsp}}kg}} are all acceptable).
 +
* Length{{ndash}}width, length{{ndash}}width{{ndash}}height and similar dimensions may be separated by the multiplication sign (<code>×</code> or <code>&amp;times;</code>) or the word '''by'''.
 
** With the multiplication sign, each number should be followed by a unit name or symbol (if appropriate):
 
** With the multiplication sign, each number should be followed by a unit name or symbol (if appropriate):
:: &nbsp; &bull; &nbsp;{{xt|1{{nbsp}}m &times; 3{{nbsp}}m &times; 6{{nbsp}}m}}, not {{nobr| {{!xt|1 &times; 3 &times; 6 m}} }}, {{!xt|(1 &times; 3 &times; 6){{nbsp}}m}} nor {{nobr| {{!xt|1 &times; 3 &times; 6{{nbsp}}m<sup>3</sup>}} }}
+
:: &nbsp; &bull; &nbsp;{{xt|1{{nbsp}}m &times; 3{{nbsp}}m &times; 6{{nbsp}}m}}, not {{!xt|1 &times; 3 &times; 6 m}}, {{!xt|(1 &times; 3 &times; 6){{nbsp}}m}} nor {{!xt|1 &times; 3 &times; 6{{nbsp}}m<sup>3</sup>}}
 
:: &nbsp; &bull; &nbsp;{{xt|a metal plate 1{{nbsp}}ft &times; 3{{nbsp}}ft &times; 0.25{{nbsp}}in}}
 
:: &nbsp; &bull; &nbsp;{{xt|a metal plate 1{{nbsp}}ft &times; 3{{nbsp}}ft &times; 0.25{{nbsp}}in}}
:: &nbsp; &bull; &nbsp;{{xt|a railroad [[easement]] 10{{nbsp}}ft &times; 2.5{{nbsp}}mi}}  
+
:: &nbsp; &bull; &nbsp;{{xt|a railroad [[Wikipedia:Easement|easement]] 10{{nbsp}}ft &times; 2.5{{nbsp}}mi}}  
:* With {{xtn|by}}, the unit need be given only once: {{nobr| {{xt|1 by 3 by 6 metres}} }} or {{nobr| {{xt|1 by 3 by 6 m}} }}
+
:* With '''by''', the unit need be given only once: {{xt|1 by 3 by 6 metres}} or {{xt|1 by 3 by 6 m}}
:* The unspaced letter {{xt|x}} may be used in common terms such as {{xt|[[4x4]]}}.
+
:* The unspaced letter {{xt|x}} may be used in common terms such as {{xt|[[Wikipedia:4x4|4x4]]}}.
  
 
{| class="wikitable"
 
{| class="wikitable"
 
|+ General guidelines on unit names and symbols
 
|+ General guidelines on unit names and symbols
 
|-
 
|-
! style="width:40px;"<!--undersized width specification means that column size is set by widest word/nobreaked phrase in column contents-->|Aspect
+
! style="width:40px;"|Aspect
! Guideline<!--this column picks up whatever width is left over from other columns-->
+
! Guideline
! style="width:40px;"<!--undersized width specification means that column size is set by widest word/nobreaked phrase in column contents-->| [[File:Yes check.svg|11px|link=|alt=]] Acceptable
+
! style="width:40px;"| Acceptable
! style="width:40px;"<!--undersized width specification means that column size is set by widest word/nobreaked phrase in column contents-->|[[File:X mark.svg|11px|link=|alt=]] Unacceptable
+
! style="width:40px;"| Unacceptable
 
|-
 
|-
 
|rowspan=6|'''Unit names and symbols'''
 
|rowspan=6|'''Unit names and symbols'''
|Except as listed in the "Specific units" table below, unit {{em|symbols}} are uncapi{{shy}}tal{{shy}}ized unless they are derived from a proper name, in which case the first letter (of the base unit symbol, not of any prefix) is capitalized.<ref>These definitions are consistent with all units of measure mentioned in the SI Brochure {{crossref|(see previous footnote)}} and with all units of measure catalogued in [[European units of measurement directives|EU directive 80/181/EEC]] [http://eur-lex.europa.eu/legal-content/EN/TXT/?qid=1397640809938&uri=CELEX:01980L0181-20090527].</ref>
+
|Unit ''symbols'' are uncapi&shy;tal&shy;ized unless they are derived from a proper name, in which case the first letter (of the base unit symbol, not of any prefix) is capitalized.<ref>These definitions are consistent with all units of measure mentioned in the SI Brochure ''(see previous footnote)'' and with all units of measure catalogued in [[Wikipedia:European units of measurement directives|EU directive 80/181/EEC]] [http://eur-lex.europa.eu/legal-content/EN/TXT/?qid=1397640809938&uri=CELEX:01980L0181-20090527].</ref>
 
| {{ xt|8 kg}}<br/>{{ xt|100 kPa}}
 
| {{ xt|8 kg}}<br/>{{ xt|100 kPa}}
 
| {{!xt|8 Kg}}<br/>{{!xt|100 kpa}}
 
| {{!xt|8 Kg}}<br/>{{!xt|100 kpa}}
Line 495: Line 381:
 
|{{!xt|38 cm<big>.</big> of rope}}
 
|{{!xt|38 cm<big>.</big> of rope}}
 
|-
 
|-
|Unit {{em|names}} are given in lower case except: where any word would be capital{{shy}}ized, or where otherwise specified in the SI brochure<ref name="SI Brochure">{{cite book |title=SI Brochure: The International System of Units (SI) |edition=8th |orig-year=2006 |year=2014 |publisher=[[Bureau International des Poids et Mesures|BIPM]] |url= http://www.bipm.org/en/publications/si-brochure/ |section=Chapter 4: Non-SI units accepted for use with the SI, and units based on fundamental constants (contd.) |section-url= http://www.bipm.org/en/publications/si-brochure/chapter4.html |accessdate=2015-08-20}} Tables 6, 7, 8, and 9 give additional guidance on non-SI units.</ref> or this Manual of Style.{{clarify}}
+
|Unit ''names'' are given in lower case except: where any word would be capital&shy;ized, or where otherwise specified in the SI brochure or this Manual of Style.
|{{plainlist|
+
|
* {{ xt|He walked several miles.}}
+
* {{xt|He walked several miles.}}<br>
* {{ xt|Miles of trenches were dug.}}
+
* {{xt|Miles of trenches were dug.}}
}}
 
 
|{{!xt|A Gallon equals 4{{nbsp}}Quarts.}}
 
|{{!xt|A Gallon equals 4{{nbsp}}Quarts.}}
 
|-
 
|-
|The spelling of certain unit names (some of which are listed in {{section link||Specific units}}, below) varies with the [[Wikipedia:Manual of Style#National varieties of English|variety of English followed by the article]].
+
|The spelling of certain unit names (some of which are listed in {{section link||Specific units}}, below) varies with the [[UniWiki:Manual of Style#National varieties of English|variety of English followed by the article]].
 
|
 
|
 
|
 
|
 
|-
 
|-
|rowspan=2 | Write unit names and symbols in upright ([[Roman type|{{sic|hide=y|roman}}]]) type, except where emphasizing in context.  
+
|rowspan=2 | Write unit names and symbols in upright ([[Wikipedia:Roman type|roman]]) type, except where emphasizing in context.  
 
| {{ xt|10{{nbsp}}m}}<br/>{{ xt|29 kilograms}}
 
| {{ xt|10{{nbsp}}m}}<br/>{{ xt|29 kilograms}}
| {{!xt|10{{nbsp}}{{em|m}}}}<br/>{{!xt|29 {{em|kilograms}}}}
+
| {{!xt|10{{nbsp}}''m''}}<br/>{{!xt|29 ''kilograms''}}
 
|-
 
|-
| {{ xt|Thus each two-liter jug contained only two {{em|quarts}}.}}
+
| {{ xt|Thus each two-liter jug contained only two ''quarts''.}}
 
|
 
|
 
|-
 
|-
 
|rowspan=8|'''Numeric values'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
 
|rowspan=8|'''Numeric values'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
|Do not spell out numbers before unit {{em|symbols}}{{nbsp}}...
+
|Do not spell out numbers before unit ''symbols''{{nbsp}}...
 
|{{ xt|12{{nbsp}}min}}
 
|{{ xt|12{{nbsp}}min}}
 
|{{!xt|twelve{{nbsp}}min}}
 
|{{!xt|twelve{{nbsp}}min}}
 
|-
 
|-
|...{{nbsp}}but words {{em|or}} figures may be used with unit {{em|names}}.  
+
|...{{nbsp}}but words ''or'' figures may be used with unit ''names''.  
|{{plainlist|
+
|
* {{ xt|twelve minutes}}
+
* {{xt|twelve minutes}}
* {{ xt|12 minutes}}
+
* {{xt|12 minutes}}
}}
 
 
|
 
|
 
|-
 
|-
Line 529: Line 413:
 
| {{!xt|Set the pointer to five.}}  
 
| {{!xt|Set the pointer to five.}}  
 
|-
 
|-
| Use a nonbreaking space ({{t|nbsp}} or <code>&amp;nbsp;</code>) between a number and a unit {{em|symbol}}, or use {{t|nowrap}}{{nbsp}}...
+
| Use a nonbreaking space ({{t|nbsp}} or <code>&amp;nbsp;</code>) between a number and a unit ''symbol'',{{nbsp}}...
| {{xt|29{{nbsp}}kg}}<br/>(markup: <code>29&amp;nbsp;kg</code> or {{nowr|<code><nowiki>{{nowrap|29 kg}}</nowiki></code>}})
+
| {{xt|29{{nbsp}}kg}}<br/>(markup: <code>29&amp;nbsp;kg</code> or <code><nowiki>29 kg</nowiki></code>)
 
| style="vertical-align: top"| {{!xt|29kg}}
 
| style="vertical-align: top"| {{!xt|29kg}}
 
|-
 
|-
 
| ... though with certain symbols ''no'' space is used (see "Specific{{nbsp}}units" table below){{nbsp}}...
 
| ... though with certain symbols ''no'' space is used (see "Specific{{nbsp}}units" table below){{nbsp}}...
| {{nobr|{{xt|23&deg;}} {{xt|47&prime;}} {{xt|22&Prime;}} }}
+
| {{xt|23&deg;}} {{xt|47&prime;}} {{xt|22&Prime;}}
| {{nobr|{{!xt|23{{nbsp}}&deg;}} {{!xt|47{{nbsp}}&prime;}} {{!xt|22{{nbsp}}&Prime;}} }}
+
| {{!xt|23{{nbsp}}&deg;}} {{!xt|47{{nbsp}}&prime;}} {{!xt|22{{nbsp}}&Prime;}}
 
|-
 
|-
| ... a normal space is used between a number and a unit {{em|name}}.
+
| ... a normal space is used between a number and a unit ''name''.
 
| {{xt|29{{nbsp}}kilograms}}<br/>(markup: <code>29&nbsp;kilograms</code>)
 
| {{xt|29{{nbsp}}kilograms}}<br/>(markup: <code>29&nbsp;kilograms</code>)
 
|
 
|
 
|-
 
|-
|To form a value and a unit {{em|name}} into a compound adjective use a hyphen or hyphens{{nbsp}}...
+
|To form a value and a unit ''name'' into a compound adjective use a hyphen or hyphens{{nbsp}}...
|{{plainlist|
+
|
* {{ xt|a five-day holiday}}
+
* {{xt|a five-day holiday}}
* {{ xt|a five-cubic-foot box}}
+
* {{xt|a five-cubic-foot box}}
* {{ xt|a 10-centimeter blade}}
+
* {{xt|a 10-centimeter blade}}
}}
 
 
|
 
|
 
|-
 
|-
|... but a non-breaking space (never hyphen) separates a value and unit {{em|symbol}}.
+
|... but a non-breaking space (never hyphen) separates a value and unit ''symbol''.
|{{plainlist|
+
|
* {{ xt|a blade 10 cm long}}<!-- What about "a 10 cm bridge"? -->
+
* {{xt|a blade 10 cm long}}
}}
 
 
| {{!xt|a 10-cm blade}}
 
| {{!xt|a 10-cm blade}}
 
|-
 
|-
 
|rowspan=5| '''Plurals'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
 
|rowspan=5| '''Plurals'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
|[[International System of Units|SI]] unit {{em|names}} are pluralized by adding the appropriate {{xt|-s}} or {{xt|-es}} suffix{{nbsp}}...<!--Not that it matters much, but I'm having trouble finding an SI unit taking -es. -->
+
|[[Wikipedia:International System of Units|SI]] unit ''names'' are pluralized by adding the appropriate {{xt|-s}} or {{xt|-es}} suffix{{nbsp}}...
|{{ xt|1 ohm}}; {{xt|10 ohms}}<!--What's an example with "-es"?-->
+
|{{ xt|1 ohm}}; {{xt|10 ohms}}
 
|
 
|
 
|-
 
|-
 
| ... except for these irregular forms.
 
| ... except for these irregular forms.
| {{ xt|1 henry}}; {{ xt|10 henries}}<br/>{{ xt|1 hertz}}; {{ xt|10 hertz }}<br/>{{ xt|1 lux}}; {{xt|10 lux}}<br/>{{ xt|1 siemens}}; {{xt|10 siemens}}
+
| {{ xt|1 henry}}; {{xt|10 henries}}<br/>{{xt|1 hertz}}; {{xt|10 hertz}}<br/>{{xt|1 lux}}; {{xt|10 lux}}<br/>{{xt|1 siemens}}; {{xt|10 siemens}}
|{{!xt|10 henrys }}<br/>{{!xt|10 hertzes}}<br/>{{!xt|10 luxes}}<br/>{{nbsp}}<!--dummy fourth line keeps content lined up with prior column-->
+
|{{!xt|10 henrys}}<br/>{{!xt|10 hertzes}}<br/>{{!xt|10 luxes}}<br/>{{nbsp}}
 
|-
 
|-
 
|rowspan=2 | Some non-SI units have irregular plurals.<!-- This is meant to be placeholder which perhaps someone can expand (though foot, feet is the only example I can think of at the moment). -->
 
|rowspan=2 | Some non-SI units have irregular plurals.<!-- This is meant to be placeholder which perhaps someone can expand (though foot, feet is the only example I can think of at the moment). -->
Line 571: Line 453:
 
| {{!xt|10 stratums}}
 
| {{!xt|10 stratums}}
 
|-
 
|-
|Unit {{em|symbols}} (in any system) are identical in singular and plural.
+
|Unit ''symbols'' (in any system) are identical in singular and plural.
|{{plainlist|
+
|
* {{nobr|{{xt|grew from 1 in to 2 in}} }}
+
* {{xt|grew from 1 in to 2 in}}
* {{nobr|{{xt|grew from 1 inch to 2 inches}} }}
+
* {{xt|grew&nbsp;from&nbsp;1&nbsp;inch&nbsp;to&nbsp;2&nbsp;inches}}
* {{nobr|{{xt|grew from one to two inches}} }}
+
* {{xt|grew from one to two inches}}
}}
+
|{{!xt|grew from 1 in to 2 ins}}
|{{nobr|{{!xt|grew from 1 in to 2 ins}} }}
 
 
|-
 
|-
 
|rowspan=5|'''Powers'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
 
|rowspan=5|'''Powers'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
Line 584: Line 465:
 
|{{!xt|km&#178;}}<br/>(<code><s>km&amp;#178;</s></code>)
 
|{{!xt|km&#178;}}<br/>(<code><s>km&amp;#178;</s></code>)
 
|-
 
|-
|Or use {{xtn|squared}} or {{xtn|cubed}} ({{em|after}} the unit being modified).
+
|Or use '''squared''' or '''cubed''' (''after'' the unit being modified).
|rowspan=2|{{xt|ten metres per second squared}}
+
|rowspan=2|{{xt|ten&nbsp;metres&nbsp;per&nbsp;second squared}}
 
|{{!xt|ten metres per squared second}}
 
|{{!xt|ten metres per squared second}}
 
|-
 
|-
|rowspan=2| For areas or volumes only, {{xtn|square}} or {{xtn|cubic}} may be used ({{em|before}} the unit being modified).
+
|rowspan=2| For areas or volumes only, '''square''' or '''cubic''' may be used (''before'' the unit being modified).
 
|{{!xt|ten metres per square second}}
 
|{{!xt|ten metres per square second}}
 
|-
 
|-
Line 594: Line 475:
 
|
 
|
 
|-
 
|-
| {{xtn|sq}} or {{xtn|cu}} may be used with US customary or imperial units, but not with [[International System of Units|SI]] units.
+
| '''sq''' or '''cu''' may be used with US customary or imperial units, but not with [[Wikipedia:International System of Units|SI]] units.
 
| {{ xt|15{{nbsp}}sq{{nbsp}}mi}}<br/>{{ xt|3{{nbsp}}cu{{nbsp}}ft }}
 
| {{ xt|15{{nbsp}}sq{{nbsp}}mi}}<br/>{{ xt|3{{nbsp}}cu{{nbsp}}ft }}
 
| {{!xt|15{{nbsp}}sq{{nbsp}}km}}<br/>{{!xt|3{{nbsp}}cu{{nbsp}}m  }}
 
| {{!xt|15{{nbsp}}sq{{nbsp}}km}}<br/>{{!xt|3{{nbsp}}cu{{nbsp}}m  }}
 
|-
 
|-
 
|rowspan=4|'''Products'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
 
|rowspan=4|'''Products'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
|Indicate a product of unit {{em|names}} with either a hyphen or a space.
+
|Indicate a product of unit ''names'' with either a hyphen or a space.
|{{plainlist|
+
|
* {{ xt|foot-pound}}
+
* {{xt|foot-pound}}
* {{ xt|foot pound}}
+
* {{xt|foot pound}}
}}
+
|
|{{plainlist|
+
* {{!xt|footpound}}
* {{!xt|footpound       }}
 
 
* {{!xt|foot&middot;pound}}
 
* {{!xt|foot&middot;pound}}
}}
 
 
|-
 
|-
|Indicate a product of unit {{em|symbols}} with <code>&amp;[[middle dot|middot]];</code> or <code>&amp;[[non-breaking space|nbsp]];</code> ({{em|Note:}} {{tlx|middot}} is not equivalent to <code>&amp;middot;</code>.)
+
|Indicate a product of unit ''symbols'' with <code>&amp;[[Wikipedia:middle dot|middot]];</code> or <code>&amp;[[Wikipedia:non-breaking space|nbsp]];</code>
|{{plainlist|1=  <!-- 1= is needed because text below contains =  -->
+
|
* {{ xt|ms       }} = millisecond
+
* {{xt|ms}} = millisecond
* {{ xt|m&middot;s}} or {{xt|m{{nbsp}}s}} = metre-second  
+
* {{xt|m&middot;s}} or {{xt|m{{nbsp}}s}} = metre-second  
}}
 
 
|
 
|
 
|-
 
|-
|{{em|Exception:}} In some topic areas such as power engineer{{shy}}ing, certain products take neither space nor <code>&amp;middot;</code>. Follow the practice of reliable sources in the article's topic area.
+
|''Exception:'' In some topic areas such as power engineer&shy;ing, certain products take neither space nor <code>&amp;middot;</code>. Follow the practice of reliable sources in the article's topic area.
|{{plainlist|
+
|
* [[watt hour|{{xt|Wh}}]], [[volt ampere|{{xt|VA}}]], [[ampere hour|{{xt|Ah}}]]
+
* [[Wikipedia:watt hour|{{xt|Wh}}]], [[Wikipedia:volt ampere|{{xt|VA}}]], [[Wikipedia:ampere hour|{{xt|Ah}}]]
 
* {{xt|kWh}}, {{xt|MVA}}, {{xt|GAh}}
 
* {{xt|kWh}}, {{xt|MVA}}, {{xt|GAh}}
}}
 
 
|
 
|
 
|-
 
|-
|To pluralize a product of unit {{em|names}}, pluralize only the final unit. (Unit {{em|symbols}} are never pluralized.)
+
|To pluralize a product of unit ''names'', pluralize only the final unit. (Unit ''symbols'' are never pluralized.)
|{{ xt|ten foot-pounds}}
+
|{{xt|ten foot-pounds}}
 
|{{!xt|ten feet-pounds}}
 
|{{!xt|ten feet-pounds}}
 
|-
 
|-
 
|rowspan=7|'''Ratios,<br />Rates,<br />Densities'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
 
|rowspan=7|'''Ratios,<br />Rates,<br />Densities'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
|Indicate a ratio of unit {{em|names}} with {{xtn|per}}.
+
|Indicate a ratio of unit ''names'' with '''per'''.
 
|{{ xt|meter per second}}
 
|{{ xt|meter per second}}
 
|{{!xt|meter/second}}
 
|{{!xt|meter/second}}
 
|-
 
|-
|rowspan=2|Indicate a ratio of unit {{em|symbols}} with a forward slash (<code>/</code>), followed by either a single symbol or a parenthesized product of symbols{{snd}}do not use multiple slashes. Or use{{nbsp}}<sup>&minus;1</sup>,{{nbsp}}<sup>&minus;2</sup>, etc.
+
|rowspan=2|Indicate a ratio of unit ''symbols'' with a forward slash (<code>/</code>), followed by either a single symbol or a parenthesized product of symbols - do not use multiple slashes. Or use{{nbsp}}<sup>&minus;1</sup>,{{nbsp}}<sup>&minus;2</sup>, etc.
|{{plainlist|
+
|
* {{ xt|metre per second}}
+
* {{xt|metre per second}}
* {{ xt|m/s}}
+
* {{xt|m/s}}
* {{ xt|m&middot;s<sup>&minus;1</sup>}}
+
* {{xt|m&middot;s<sup>&minus;1</sup>}}
}}
+
|
|{{plainlist|
 
 
* {{!xt|mps}}
 
* {{!xt|mps}}
}}
 
 
|-
 
|-
|{{plainlist|
+
|
* {{ xt|kg/(m&middot;s)}}
+
* {{xt|kg/(m&middot;s)}}
* {{ xt|kg&middot;m<sup>&minus;1</sup>&middot;s<sup>&minus;1</sup>}}
+
* {{xt|kg&middot;m<sup>&minus;1</sup>&middot;s<sup>&minus;1</sup>}}
}}
+
|
|{{plainlist|
 
 
* {{!xt|kg/m&middot;s}}
 
* {{!xt|kg/m&middot;s}}
* {{!xt|kg/m/s       }}
+
* {{!xt|kg/m/s}}
}}
 
 
|-
 
|-
|To pluralize a ratio of unit {{em|names}}, pluralize only the numerator unit. (Unit {{em|symbols}} are never pluralized.)
+
|To pluralize a ratio of unit ''names'', pluralize only the numerator unit. (Unit ''symbols'' are never pluralized.)
|{{plainlist|
+
|
* {{nowrap|{{xt|ten newton-metres per second}} }}<!-- Nowrap on longest value in column establishes minimum col width. -->
+
* {{xt|ten newton-metres per second}}
 
* {{xt|10 N&middot;m/s}}
 
* {{xt|10 N&middot;m/s}}
}}
 
 
|
 
|
 
|-
 
|-
 
|Some of the special forms used in the imperial and US customary systems are shown here{{nbsp}}...  
 
|Some of the special forms used in the imperial and US customary systems are shown here{{nbsp}}...  
|{{plainlist|1=  <!--  1= is needed because text below contains =  -->
+
|
* {{ xt|mph}} = miles per hour
+
* {{xt|mph}} = miles per hour
* {{ xt|mpg}} = miles per gallon
+
* {{xt|mpg}} = miles per gallon
* {{ xt|psi}} = [[pound (force)|pound]]s per square inch
+
* {{xt|psi}} = [[Wikipedia:pound (force)|pounds]] per square inch
}}
 
 
|
 
|
 
|-
 
|-
 
|rowspan=2| ... but only the slash or negative exponent notations are used with SI (and other metric) units.
 
|rowspan=2| ... but only the slash or negative exponent notations are used with SI (and other metric) units.
| {{plainlist|
+
|
* {{ xt|g/m<sup>2</sup>             }}
+
* {{xt|g/m<sup>2</sup>}}
* {{ xt|g&middot;m<sup>&minus;2</sup>}}
+
* {{xt|g&middot;m<sup>&minus;2</sup>}}
}}
 
 
| {{!xt|gsm}}
 
| {{!xt|gsm}}
 
|-
 
|-
| {{plainlist|
+
|
* {{ xt|km/h                         }}
+
* {{xt|km/h}}
* {{ xt|km&middot;h<sup>&minus;1</sup>}}
+
* {{xt|km&middot;h<sup>&minus;1</sup>}}
}}
 
 
| {{!xt|kph}}
 
| {{!xt|kph}}
 
|-
 
|-
Line 682: Line 551:
 
|Prefixes should not be separated by a space or hyphen.
 
|Prefixes should not be separated by a space or hyphen.
 
|{{ xt|25 kilopascals}}
 
|{{ xt|25 kilopascals}}
|{{plainlist|
+
|
 
* {{!xt|25 kilo pascals}}
 
* {{!xt|25 kilo pascals}}
 
* {{!xt|25 kilo-pascals}}
 
* {{!xt|25 kilo-pascals}}
}}
 
 
|-
 
|-
| Prefixes are added without contraction,<!--give example--> except as shown here:
+
| Prefixes are added without contraction, except as shown here:
 
| {{ xt|kilohm }}<br/>{{ xt|megohm }}<br/>{{xt|hectare}}
 
| {{ xt|kilohm }}<br/>{{ xt|megohm }}<br/>{{xt|hectare}}
 
| {{!xt|kiloohm}}<br/>{{!xt|megaohm}}<br/>{{!xt|hectoare}}
 
| {{!xt|kiloohm}}<br/>{{!xt|megaohm}}<br/>{{!xt|hectoare}}
 
|-
 
|-
|The {{xtn|centi-}}, {{xtn|deci-}}, {{xtn|deca-}}, and {{xtn|hecto-}} prefixes should generally be avoided; exceptions include<!--Check SI source; also, since we're supposed to follow the units in sources, don't those control anyway?--> centimetre, decibel, hectolitre, hectare, and hectopascal.
+
|The '''centi-''', '''deci-''', '''deca-''', and '''hecto-''' prefixes should generally be avoided; exceptions include centimetre, decibel, hectolitre, hectare, and hectopascal.
|{{plainlist|
+
|
* {{ xt|100 metres}}
+
* {{xt|100 metres}}
* {{ xt|0.1 km}}
+
* {{xt|0.1 km}}
}}
 
 
|{{!xt|1 hectometre}}
 
|{{!xt|1 hectometre}}
 
|-
 
|-
| Do not use [[wikt:M#Number|{{!xt|M}}]] for 10<sup>3</sup>, {{!xt|MM}} for 10<sup>6</sup>, or {{!xt|B}} for 10<sup>9</sup> (except as noted elsewhere on this page for {{xtn|M}} and {{xtn|B}}, e.g. [[#Currencies and monetary values|for monetary values]])
+
| Do not use [[wikt:M#Number|{{!xt|M}}]]
| {{ xt|3 km   }}<br/>{{ xt|8 MW   }}<br/>{{ xt|125 GeV}}
+
for 10<sup>3</sup>, {{!xt|MM}} for 10<sup>6</sup>, or {{!xt|B}} for 10<sup>9</sup> (except as noted elsewhere on this page for '''M''' and '''B''', e.g. [[#Currencies and monetary values|for monetary values]])
| {{!xt|3 Mm   }}<br/>{{!xt|8 MMW }}<br/>{{!xt|125 BeV}}
+
| {{xt|3 km}}<br/>{{ xt|8 MW}}<br/>{{ xt|125 GeV}}
 +
| {{!xt|3 Mm}}<br/>{{!xt|8 MMW}}<br/>{{!xt|125 BeV}}
 
|-
 
|-
 
|rowspan=4|'''Mixed<br />units'''<!-- ← Use <br /> to make this column as narrow as possible.--><!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
 
|rowspan=4|'''Mixed<br />units'''<!-- ← Use <br /> to make this column as narrow as possible.--><!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES -->
 
|rowspan=2| Mixed units are traditionally used with the imperial and US customary systems{{nbsp}}...
 
|rowspan=2| Mixed units are traditionally used with the imperial and US customary systems{{nbsp}}...
|{{anchor|Mixed units}}<!-- ← This anchor should go at the portion of the row which is vertically highest. -->{{plainlist|
+
|
 
* {{xt|a wall 1 ft 1 in thick}}
 
* {{xt|a wall 1 ft 1 in thick}}
* {{xt|a wall 1 foot 1 inch thick }}  
+
* {{xt|a wall 1 foot 1 inch thick}}  
 
* {{xt|a man 6 feet 2 inches tall}}
 
* {{xt|a man 6 feet 2 inches tall}}
 
* {{xt|a 6-foot 2-inch man}}
 
* {{xt|a 6-foot 2-inch man}}
 
* {{xt|a 6 ft 2 in man}}
 
* {{xt|a 6 ft 2 in man}}
}}
+
|
|{{plainlist|
+
* {{!xt|1&nbsp;ft,&nbsp;1&nbsp;in}}&nbsp;(no&nbsp;comma)
* {{nobr| {{!xt|1 ft{{hsp}}, 1 in   }} (no comma) }}
+
* {{!xt|1 foot, 1 inch}}
* {{!xt|1 foot{{hsp}}, 1 inch}}
 
 
* {{!xt|a man 6 foot 2 tall}}
 
* {{!xt|a man 6 foot 2 tall}}
* {{!xt|a 6-foot 2 man}}
+
* {{!xt|a 6-foot 2 man}}<br>{{nbsp}}
* {{nbsp}}
 
}}
 
 
|-
 
|-
|{{plainlist|
+
|
 
* {{xt|1 US fl pt 8 oz}}
 
* {{xt|1 US fl pt 8 oz}}
 
* {{xt|1 US fl pt 8 US fl oz}}
 
* {{xt|1 US fl pt 8 US fl oz}}
}}
 
 
|
 
|
 
|-
 
|-
 
|... and in expressing time durations{{nbsp}}...
 
|... and in expressing time durations{{nbsp}}...
|{{plainlist|
+
|
 
* {{xt|1:30:07}}
 
* {{xt|1:30:07}}
* {{xt|1:30}}{{thinsp}}<ref group="note">Only use this format if it is clear from the context whether this means hours and minutes (H:MM) or minutes and seconds (M:SS).</ref>
+
* {{xt|1:30}}&thinsp;<ref>Only use this format if it is clear from the context whether this means hours and minutes (H:MM) or minutes and seconds (M:SS).</ref>
* {{xt|{{nobr|1 h 30 min 7 s}}}}
+
* {{xt|1 h 30 min 7 s}}
* {{xt|{{nobr|01<sup>h</sup> 30<sup>m</sup> 07<sup>s</sup>}}}}{{thinsp}}{{refn|group=note|This format is used in astronomy (see the IAU Style Manual<ref>{{cite book |title=IAU Style Manual |first=G. A. |last=Wilkins |section=5.14 Time and angle |page=S23 |year=1989 |url=https://www.iau.org/static/publications/stylemanual1989.pdf}}</ref> for details).}}
+
* {{xt|01<sup>h</sup> 30<sup>m</sup> 07<sup>s</sup>}}&thinsp;<ref>This format is used in astronomy (see the IAU Style Manual for details).</ref>
}}
+
||
||{{plainlist|
+
* {{!xt|1:30&prime;07&Prime;}}
* {{!xt|{{nobr|1:30&prime;07&Prime;}}}}
+
* {{!xt|1 hr 30 min 7 sec}}
* {{!xt|{{nobr|1 hr 30 min 7 sec}}}}
+
* {{!xt|1 h 30 m 7 s}}
* {{!xt|{{nobr|1 h 30 m 7 s}}}}
 
}}
 
 
|-
 
|-
 
|... but are not normally used in SI.
 
|... but are not normally used in SI.
|{{plainlist|
+
|
 
* {{xt|1.33 m  }}
 
* {{xt|1.33 m  }}
 
* {{xt|133 cm  }}
 
* {{xt|133 cm  }}
}}
 
 
|{{!xt|1 m 33 cm}}
 
|{{!xt|1 m 33 cm}}
 
|}
 
|}
{{em|Note to table:}}
 
{{reflist | group=note}}
 
  
===Specific units===
+
====Quantities of bytes and bits====
* The following table lists only units that need special attention.
 
* The SI Brochure<ref name="SI Brochure" /> should be consulted for guidance on use of other SI and non-SI units.
 
  
{|class="wikitable"
+
In quantities of [[Wikipedia:bit (computing)|bit]]s and [[Wikipedia:Byte|byte]]s, the prefixes '''kilo-''' (symbol '''k''' or '''K'''), '''mega-''' ('''M'''), '''giga-''' ('''G'''), '''tera-''' ('''T'''), etc., are ambiguous. They may be based on a decimal system (like the standard [[Wikipedia:International System of Units|SI]] prefixes), meaning 10<sup>3</sup>, 10<sup>6</sup>, 10<sup>9</sup>, 10<sup>12</sup>, etc., or they may be based on a binary system, meaning 2<sup>10</sup>, 2<sup>20</sup>, 2<sup>30</sup>, 2<sup>40</sup>, etc. The binary meanings are more commonly used in relation to solid-state memory (such as [[Wikipedia:Random-access memory|RAM]]), while the decimal meanings are more common for data transmission rates, disk storage and in theoretical calculations in modern academic textbooks.
|+ Guidelines on specific units
 
|-
 
! style="width:40px;"<!--undersized width specification means that column size is set by widest word/nobreaked phrase in column contents-->| Group
 
! style="width:40px;"<!--undersized width specification means that column size is set by widest word/nobreaked phrase in column contents-->| Name
 
! style="width:40px;"<!--undersized width specification means that column size is set by widest word/nobreaked phrase in column contents-->| Symbol
 
! Comment<!--this column picks up whatever width is left over from other columns-->
 
|-
 
| rowspan = 11 | '''Length''',<br />'''Speed'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS -->
 
| inch
 
| {{ xt|in}}
 
| rowspan=2|Do not use <code>&amp;prime;</code>{{nbsp}}({{!xt|&prime;}}), <code>&amp;Prime;</code>{{nbsp}}({{!xt|&Prime;}}), apostrophe{{nbsp}}({{!xt|'}}) or quote{{nbsp}}({{!xt|"}}).
 
|-
 
| foot
 
| {{ xt|ft}}
 
|-
 
| foot per second
 
| {{ xt|ft/s}} ({{em|not}} {{!xt|fps}})
 
|
 
|-
 
| [[Hand (unit)|hand]]
 
| {{xt|h}} or {{ xt|hh}}
 
| Equal to 4 inches; used in measurement of horses. A dot may be followed by additional inches e.g. {{nobr|{{xt|16.2 hh}}}} indicates {{nobr|16 hands 2 inches.}}
 
|-
 
| knot
 
| {{xt|kn}} ({{em|not}} {{!xt| [[kilotonne|kt]]}} or {{!xt|[[kilonewton|kN]]}})<!--not sure how to resolve the conflicting coloration desiderata-->
 
|
 
|-
 
| {{plainlist|
 
* metre
 
* meter {{em|(U.S.)}}
 
}}
 
| {{xt|m}}
 
|
 
|-
 
| micron
 
| {{xt|&mu;m}} ({{em|not}} {{!xt|&mu;}})
 
| Markup: <code>&amp;mu;m</code>{{nbsp}} Link to [[micrometre]] (for which micron is a synonym) on first use.
 
|-
 
| [[astronomical unit]]
 
| {{xt|AU}} {{nobr| ({{em|not}} {{!xt|A.U.}}, {{!xt|au}}, {{!xt|ua}}) }}
 
| {{xtn|AU}} is the most commonly used unit symbol for the astronomical unit, both in popular and professional astronomical articles, and is hence also used on Wikipedia, although some organizations, including the [[Bureau International des Poids et Mesures|BIPM]]<ref name="SI Brochure" /> and [[International Astronomical Union|IAU]],<ref>{{cite web |title=Resolution B2 on the re-definition of the astronomical unit of length |url=http://www.iau.org/static/resolutions/IAU2012_English.pdf#page=3 |page=1 |year=2012 |website=International Astronomical Union}}</ref> recommend {{xtn|au}}.
 
|-
 
| mile
 
| {{xt|mi}}
 
|rowspan=3 | In nautical and aeronautical contexts use {{xt|statute mile}}<!-- ← Should this be an entry in the table? --> rather than mile to avoid confusion with nautical mile.
 
|-
 
| mile per hour
 
| {{xt|mph}}<!-- not ever mi/hr??-->
 
|-
 
| nautical mile
 
| {{nobr| {{xt|nmi}} or {{xt|NM}} {{nobr|({{em|not}} {{!xt|[[nanometre|nm]]}})}} }}
 
|-
 
| rowspan = 13 | '''Volume''',<br />'''Flow'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS -->
 
| rowspan = 2 | {{plainlist|
 
* cubic centimetre
 
* {{nobr| cubic centimeter {{em|(U.S.)}} }}
 
}}
 
| {{xt|cm<sup>3</sup>}}
 
| Markup: <code><nowiki>cm<sup>3</sup></nowiki></code>
 
|-
 
| {{xt|cc}}
 
| Non-SI symbol used for certain [[engine displacement]]s; link to [[Cubic centimetre]] on first use.<!-- I wonder if this can't be better coordinated with mpg, mph etc in earlier table. -->
 
|-
 
| imperial fluid ounce
 
| {{xt|imp fl oz}}
 
| rowspan=8 | {{xtn|US}} or {{xtn|imperial}} (or {{xtn|imp}}) must be specified; {{xtn|fluid}} or {{xtn|fl}} must be specified for fluid ounces and US units, except with gallon. (Without {{xtn|fluid}}, [[ounce]] is ambiguous{{snd}}versus avoirdupois ounce or troy ounce{{snd}}and US [[pint]] or US [[quart]] are ambiguous{{snd}}versus US dry pint or US dry quart.)
 
|-
 
| imperial pint
 
| {{xt|imp pt}}
 
|-
 
| imperial quart
 
| {{xt|imp qt}}
 
|-
 
| imperial gallon
 
| {{xt|imp gal}}
 
|-
 
| US fluid ounce
 
| {{xt|US fl oz}}
 
|-
 
| US fluid pint
 
| {{xt|US fl pt}}
 
|-
 
| US fluid quart
 
| {{xt|US fl qt}}
 
|-
 
| US gallon
 
| {{xt|US gal}}
 
|-
 
| cubic foot
 
| {{xt|cu ft}} ({{em|not}} {{!xt|cf}})
 
| Write {{xt|five million cubic feet}}, {{xt|5,000,000{{nbsp}}cu{{nbsp}}ft}} or {{xt|{{val|5|e=6|u=cuft}}}}, not {{!xt|5{{nbsp}}MCF}}.
 
|-
 
| {{nobr| cubic foot per second }}
 
| {{xt|cu ft/s}} ({{em|not}} {{!xt|cfs}})
 
|
 
|-
 
| {{plainlist|
 
* litre
 
* liter {{em|(U.S.)}}
 
}}
 
| {{xt|l}} or {{xt|L}}
 
| The symbol l ("el") in isolation (i.e. not in such forms as ml) is easily mistaken for the digit{{nbsp}}1 or the capital letter{{nbsp}}I{{nbsp}}("eye").
 
|-
 
| rowspan=7 | '''Mass''',<br />'''Force''',<br />'''Density''',<br />'''Pressure'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS -->
 
| [[long ton]]
 
| {{xt|long ton}}
 
| rowspan=2 | Spell out in full.
 
|-
 
| [[short ton]]
 
| {{xt|short ton}}
 
|-
 
| {{nobr| pound per square inch }}
 
| {{xt|psi}}
 
|
 
|-
 
| {{plainlist|
 
* [[tonne]]
 
* [[tonne|metric ton]] {{em|(U.S.)}}
 
}}
 
| {{xt|t}} {{nobr|({{em|not}} {{!xt|mt}} or {{!xt|MT}})}}
 
|
 
|-
 
| troy ounce
 
| {{xt|oz t}}
 
| rowspan=2 | {{xtn|t}} or {{xtn|troy}} must be specified. Articles about precious metals, black powder, and gemstones<!-- Is this list complete? --> should always specify whether ounces and pounds are [[Avoirdupois|avoirdupois]] or [[Troy weight|troy]].
 
|-
 
| troy pound
 
| {{xt|lb t}}
 
|-
 
| [[Carat (mass)|carat]]
 
| {{xt|carat}}
 
| Used to express masses of gemstones and pearls.
 
|-
 
| '''Purity'''<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS -->
 
| [[Carat (purity)|carat or karat]]
 
| {{xt|k}} or {{xt|Kt}}
 
| A measure of purity for gold alloys. (Do not confuse with the unit of mass with the same spelling.)
 
|-
 
| rowspan=5 | '''Time'''
 
| second
 
| {{xt|s}}
 
|rowspan=3|Do not use <code>&amp;prime;</code>{{nbsp}}({{!xt|&prime;}}), <code>&amp;Prime;</code>{{nbsp}}({{!xt|&Prime;}}), apostrophe{{nbsp}}({{!xt|'}}) or quote{{nbsp}}({{!xt|"}}) for minutes or seconds. See also the hours–minutes–seconds formats for time durations described in the [[#Mixed units|Unit names and symbols table]].
 
|-
 
| minute
 
| {{xt|min}}
 
|-
 
| hour
 
| {{xt|h}}
 
|-
 
| rowspan=2|year
 
| {{xt|a}}
 
| Use {{xtn|a}} only with an [[SI annus|SI prefix multiplier]] ({{xt|a rock formation 540{{nbsp}}Ma{{nbsp}}old}}, not {{!xt|Life expectancy rose to 60 a}}).
 
|-
 
| {{xt|y}} or {{xt|yr}}
 
| {{crossref|See {{section link||Long periods of time}} for all affected units.}}
 
|-
 
| rowspan=4 |<!-- WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS -->
 
'''Infor&shy;mation''', '''Data'''
 
| bit
 
| {{xt|bit}} {{nobr|({{em|not}} {{!xt|b}} or {{!xt|B}})}}
 
| rowspan=4 | {{crossref|See also {{section link||Quantities of bytes and bits}}, below.}} Do not confuse bit/second or byte/second with [[baud|baud (Bd)]].
 
|-
 
| byte
 
| {{nobr| {{xt|B}} or {{xt|byte}} ({{em|not}} {{!xt|b}} or {{!xt|[[octet (computing)|o]]}}) }}
 
|-
 
| bit per second
 
| {{xt|bit/s}} ({{em|not}} {{!xt|bps}}, {{!xt|b/s}})
 
|-
 
| byte per second
 
| {{xt|B/s}} or {{xt|byte/s}} {{nobr| ({{em|not}} {{!xt|Bps}} or {{!xt|Bps}}) }}
 
|-
 
| rowspan = 4 | '''Angle'''<!-- - - - WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS - - - -->
 
|-
 
| [[arcminute]]
 
| {{xt|&prime;}}
 
| Markup: <code>&amp;prime;</code>{{nbsp}} ([[prime (symbol)|prime&nbsp;&prime;]] not apostrophe/{{zwsp}}single quote{{nbsp}}{{!xt|'}}). {{nobr|No space  ({{xt|47&prime;}}, not {{!xt|47{{nbsp}}&prime;}}). }}
 
|-
 
| [[arcsecond]]
 
| {{xt|&Prime;}}
 
| Markup: <code>&amp;Prime;</code>{{nbsp}} ([[double prime (symbol)|double prime&nbsp;&Prime;]] not double-quote{{nbsp}}{{!xt|"}}). {{nobr|No space ({{xt|22&Prime;}}, not {{!xt|22{{nbsp}}&Prime;}}). }}
 
|-
 
| degree
 
| {{xt|&deg;}}
 
| Markup: <code>&amp;deg;</code> (degree &deg; not [[masculine ordinal]] {{!xt|&#186;}} or [[ring (diacritic)|ring]]&nbsp;{{thinsp}}{{!xt|&#778;}}{{hsp}}<!--<<hsp is needed to prevent crash between ring and closing paren, at least on some browsers-->). {{nobr|No space ({{xt|23&deg;}}, not {{!xt|23{{nbsp}}&deg;}}). }}
 
|-
 
| rowspan = 3 | '''Temp&shy;erature'''<!-- - - - WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS - - - -->
 
| degree
 
| {{xt|&deg;}}
 
| rowspan = 2 | Markup: <code>&amp;deg;</code>. Use a nonbreaking space: {{nobr|<code>12{{t|nbsp}}&amp;deg;C</code>}}, not {{nobr|<s><code>12&amp;deg;C</code></s>}} nor {{nobr|<s><code>12&amp;deg;{{t|nbsp}}C</code></s> }}
 
|-
 
| degree Celsius {{nobr|({{em|not}} degree centigrade)}}
 
| {{xt|&deg;C}} ({{em|not}} {{!xt|C}})
 
|-
 
| [[kelvin]] {{nobr|({{em|not}} degree kelvin)}}
 
| {{xt|K}} ({{em|not}} {{!xt|&deg;K}})
 
|
 
|-
 
| rowspan = 2 | '''Energy'''<!-- - - - WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS- - - -->
 
| {{plainlist|
 
* [[calorie]]
 
* small calorie
 
* gram calorie
 
}}
 
| {{xt|cal}}
 
| rowspan=2 | In certain subject areas, calorie is convention{{shy}}ally used alone. Articles following this practice should specify on first use whether the use refers to the small calorie or to the kilocalorie (large calorie). Providing conversions to [[International System of Units|SI]] units (usually calories to joules or kilocalories to kilojoules) may also be useful. A kilocalorie ({{xt|kcal}}) is 1000 calories. A calorie (small calorie) is the amount of energy required to heat 1 gram of water by 1 °C. A kilocalorie is therefore also a kilogram calorie.
 
|-
 
| {{plainlist|
 
* [[kilocalorie]]
 
* large calorie
 
* kilogram calorie
 
* ({{em|not}} Calorie{{snd}}{{nobr|can be ambiguous)}}
 
}}
 
| {{xt|kcal}}
 
|}
 
  
====Quantities of bytes and bits <span id="Binary prefixes"></span>====
+
Follow these recommendations when using these prefixes in UniWiki articles:
{{shortcut|WP:COMPUNITS}}
 
In quantities of [[bit (computing)|bit]]s and [[byte]]s, the prefixes {{xtn|kilo-}} (symbol {{xtn|k}} or {{xtn|K}}), {{xtn|mega-}} ({{xtn|M}}), {{xtn|giga-}} ({{xtn|G}}), {{xtn|tera-}} ({{xtn|T}}), etc., are ambiguous. They may be based on a decimal system (like the standard [[International System of Units|SI]] prefixes), meaning 10<sup>3</sup>, 10<sup>6</sup>, 10<sup>9</sup>, 10<sup>12</sup>, etc., or they may be based on a binary system, meaning 2<sup>10</sup>, 2<sup>20</sup>, 2<sup>30</sup>, 2<sup>40</sup>, etc. The binary meanings are more commonly used in relation to solid-state memory (such as [[Random-access memory|RAM]]), while the decimal meanings are more common for data transmission rates, disk storage and in theoretical calculations in modern academic textbooks.
 
{{Bit and byte prefixes}}
 
Follow these recommendations when using these prefixes in Wikipedia articles:
 
  
 
* Following the SI standard, a lower-case {{xt|k}} should be used for "kilo-" whenever it means 1000 in computing contexts, whereas a capital {{xt|K}} should be used instead to indicate the binary prefix for 1024 according to JEDEC. (If, under the exceptions detailed further below, the article otherwise uses IEC prefixes for binary units, use {{xt|Ki}} instead).
 
* Following the SI standard, a lower-case {{xt|k}} should be used for "kilo-" whenever it means 1000 in computing contexts, whereas a capital {{xt|K}} should be used instead to indicate the binary prefix for 1024 according to JEDEC. (If, under the exceptions detailed further below, the article otherwise uses IEC prefixes for binary units, use {{xt|Ki}} instead).
* Do not assume that the binary or decimal meaning of prefixes will be obvious to everyone. Explicitly specify the meaning of k and K as well as the primary meaning of M, G, T, etc. in an article ({{tlx|BDprefix}} is a convenient helper). Consistency within each article is desirable, but the need for consistency may be balanced with other considerations.
+
* Do not assume that the binary or decimal meaning of prefixes will be obvious to everyone. Explicitly specify the meaning of k and K as well as the primary meaning of M, G, T, etc. in an article. Consistency within each article is desirable, but the need for consistency may be balanced with other considerations.
* The definition most relevant to the article should be chosen as primary for that article, e.g. specify a binary definition in an article on RAM, decimal definition in an article on [[hard drives]], [[bit rate]]s, and a binary definition for Windows file sizes, despite files usually being stored on hard drives.
+
* The definition most relevant to the article should be chosen as primary for that article, e.g. specify a binary definition in an article on RAM, decimal definition in an article on [[Wikipedia:Hard drives|hard drives]], [[Wikipedia:Bit rate|bit rates]], and a binary definition for Windows file sizes, despite files usually being stored on hard drives.
 
* Where consistency is not possible, specify wherever there is a deviation from the primary definition.
 
* Where consistency is not possible, specify wherever there is a deviation from the primary definition.
 
* Disambiguation should be shown in bytes or bits, with clear indication of whether in binary or decimal base. There is no preference in the way to indicate the number of bytes and bits, but the notation style should be consistent within an article. Acceptable examples include:
 
* Disambiguation should be shown in bytes or bits, with clear indication of whether in binary or decimal base. There is no preference in the way to indicate the number of bytes and bits, but the notation style should be consistent within an article. Acceptable examples include:
: &nbsp; &bull; &nbsp;{{xt|A 64{{nbsp}}MB ({{nowrap|64 &times; 1024<sup>2</sup>-byte)}} video card and a 100{{nbsp}}GB {{nowrap|(100 &times; 1000<sup>3</sup>-byte)}} hard drive}}
+
: &nbsp; &bull; &nbsp;{{xt|A 64{{nbsp}}MB (64 &times; 1024<sup>2</sup>-byte) video card and a 100{{nbsp}}GB (100 &times; 1000<sup>3</sup>-byte) hard drive}}
: &nbsp; &bull; &nbsp;{{xt|A 64{{nbsp}}MB ({{nowrap|64 &times; 2<sup>20</sup>-byte)}} video card and a 100{{nbsp}}GB {{nowrap|(100 &times; 10<sup>9</sup>-byte)}} hard drive}}
+
: &nbsp; &bull; &nbsp;{{xt|A 64{{nbsp}}MB (64 &times; 2<sup>20</sup>-byte) video card and a 100{{nbsp}}GB (100 &times; 10<sup>9</sup>-byte) hard drive}}
 
: &nbsp; &bull; &nbsp;{{xt|A 64{{nbsp}}MB (67,108,864-byte) video card and a 100{{nbsp}}GB (100,000,000,000-byte) hard drive}}
 
: &nbsp; &bull; &nbsp;{{xt|A 64{{nbsp}}MB (67,108,864-byte) video card and a 100{{nbsp}}GB (100,000,000,000-byte) hard drive}}
* Avoid inconsistent combinations such as {{!xt|A 64{{nbsp}}MB (67,108,864-byte) video card and a 100{{nbsp}}GB {{nowrap|(100 &times; 1000<sup>3</sup>-byte)}} hard drive}}. Footnotes, such as those seen in [//en.wikipedia.org/w/index.php?title=Power_Macintosh_5500&oldid=218088888 {{nowrap|Power Macintosh 5500}}], may be used for disambiguation.
+
* Avoid inconsistent combinations such as {{!xt|A 64{{nbsp}}MB (67,108,864-byte) video card and a 100{{nbsp}}GB (100 &times; 1000<sup>3</sup>-byte)}} hard drive. Footnotes, such as those seen in [//en.wikipedia.org/w/index.php?title=Power_Macintosh_5500&oldid=218088888 Power Macintosh 5500], may be used for disambiguation.
* Unless explicitly stated otherwise, one byte is eight bits {{crossref|(see [[Byte#History|History of "byte"']])}}.
+
* Unless explicitly stated otherwise, one byte is eight bits ''(see [[Wikipedia:Byte#History|History of "byte"']]).
  
The [[IEC prefix]]es {{xtn|kibi-}} (symbol {{xtn|Ki}}), {{xtn|mebi-}} ({{xtn|Mi}}), {{xtn|gibi-}} ({{xtn|Gi}}), etc., are generally not to be used except:<ref>Wikipedia follows common practice regarding [[byte]]s and other data traditionally quantified using [[binary prefix]]es (e.g. {{xtn|mega-}} and {{xtn|kilo-}}, meaning 2<sup>20</sup> and 2<sup>10</sup> respectively) and their unit symbols (e.g. {{xtn|MB}} and {{xtn|KB}}) for RAM and [[decimal prefix]]es for most other uses.  Despite the IEC's 1998 international standard creating several new binary prefixes (e.g. mebi-, kibi-) to distinguish the meaning of the decimal [[SI prefix]]es (e.g. {{xtn|mega-}} and {{xtn|kilo-}}, meaning 10<sup>6</sup> and 10<sup>3</sup> respectively) from the binary ones, and the subsequent incorporation of these IEC prefixes into the [[IEC 80000-13|ISO/IEC 80000]], consensus on Wikipedia in computing-related contexts currently favours the retention of the more familiar but ambiguous units {{xtn|KB}}, {{xtn|MB}}, {{xtn|GB}}, {{xtn|TB}}, {{xtn|PB}}, {{xtn|EB}}, etc. over use of unambiguous IEC binary prefixes. {{crossref|For detailed discussion, see [[WT:Manual of Style (dates and numbers)/Archive/Complete rewrite of Units of Measurements (June 2008)]].}}</ref>
+
The [[Wikipedia:IEC prefix|IEC prefixes]] '''kibi-''' (symbol '''Ki'''), '''mebi-''' ('''Mi'''), '''gibi-''' ('''Gi'''), etc., are generally not to be used except:<ref>The UniWiki follows common practice regarding [[Wikipedia:Byte|bytes]] and other data traditionally quantified using [[Wikipedia:Binary prefix|binary prefixes]] (e.g. '''mega-''' and '''kilo-''', meaning 2<sup>20</sup> and 2<sup>10</sup> respectively) and their unit symbols (e.g. '''MB''' and '''KB''') for RAM and [[Wikipedia:Decimal prefix|decimal prefixes]] for most other uses.  Despite the IEC's 1998 international standard creating several new binary prefixes (e.g. mebi-, kibi-) to distinguish the meaning of the decimal [[Wikipedia:SI prefix|SI prefixes]] (e.g. '''mega-''' and '''kilo-''', meaning 10<sup>6</sup> and 10<sup>3</sup> respectively) from the binary ones, and the subsequent incorporation of these IEC prefixes into the [[Wikipedia:IEC 80000-13|ISO/IEC 80000]], consensus on Wikipedia in computing-related contexts currently favours the retention of the more familiar but ambiguous units '''KB''', '''MB''', '''GB''', '''TB''', '''PB''', '''EB''', etc. over use of unambiguous IEC binary prefixes.</ref>
 
* when the majority of cited sources on the article topic use IEC prefixes;
 
* when the majority of cited sources on the article topic use IEC prefixes;
 
* in a direct quote using the IEC prefixes;
 
* in a direct quote using the IEC prefixes;
Line 991: Line 630:
 
* in articles in which both types of prefix are used with neither clearly primary, or in which converting all quantities to one or the other type would be misleading or lose necessary precision, or declaring the actual meaning of a unit on each use would be impractical.
 
* in articles in which both types of prefix are used with neither clearly primary, or in which converting all quantities to one or the other type would be misleading or lose necessary precision, or declaring the actual meaning of a unit on each use would be impractical.
  
==<span id="Currencies"></span> Currencies and monetary values==
+
==Currencies and monetary values==
{{shortcut|WP:$|WP:&pound;|WP:€|MOS:CURRENCY}}
+
 
{{see also|Wikipedia:WikiProject Numismatics/Style#Article titles}}
 
 
===Choice of currency===
 
===Choice of currency===
* In '''country-specific articles''', such as [[Economy of Australia]], use the currency of the subject country.
+
* In '''country-specific articles''', such as [[Wikipedia:Economy of Australia|Economy of Australia]], use the currency of the subject country.
* In '''non-country-specific articles''' such as [[Wealth]], use US dollars ({{xt|$123}}), euros ({{xt|&euro;123}}), or pounds sterling ({{xt|&pound;123}}).
+
* In '''non-country-specific articles''' such as [[Wikipedia:Wealth|Wealth]], use US dollars ({{xt|$123}}), euros ({{xt|&euro;123}}), or pounds sterling ({{xt|&pound;123}}).
  
 
===Currency names===
 
===Currency names===
* Do not capitalize the names or denominations of currencies, currency subdivisions, coins and banknotes: not {{!xt|a Five-Dollar bill, four Quarters, and one Penny total six Dollars one Cent}} but {{xt|a five-dollar bill, four quarters, and one penny total six dollars one cent}}. ''Exception:'' where otherwise required, as at the start of a sentence or in such forms as {{xt|Australian dollar}}.
+
* Do not capitalize the names or denominations of currencies, currency subdivisions, coins and banknotes: not {{!xt|a Five-Dollar bill, four Quarters, and one Penny total six Dollars one Cent}} but {{xt|a five-dollar bill, four quarters, and one penny total six dollars one cent}}. ''Exception:'' where otherwise required, as at the start of a sentence or in such forms as {{xt|Interstellar Kredits}}.
* To pluralize {{xtn|euro}} use the standard English plurals ({{xt|ten euros and fifty cents}}), not the [[Linguistic issues concerning the euro#English|invariant plurals used for European Union legislation and banknotes]] ({{!xt|ten euro and fifty cent}}). For the adjectival form, use a hyphenated singular: ({{xt|a two-euro pen and a ten-cent coin}}).  
+
* To pluralize '''euro''' use the standard English plurals ({{xt|ten euros and fifty cents}}), not the [[Wikipedia:Linguistic issues concerning the euro#English|invariant plurals used for European Union legislation and banknotes]] ({{!xt|ten euro and fifty cent}}). For the adjectival form, use a hyphenated singular: ({{xt|a two-euro pen and a ten-cent coin}}).
* Link the first occurrence of lesser-known currencies ({{xt|[[Mongolian tögrög]]s}}).<!-- Should a symbol be introduced at this time? -->
 
  
===Currency symbols===<!-- Symbols, signifiers, abbreviations? See [[ISO 4217]] and [[currency symbol]]s. -->
+
===Currency symbols===
* In general, the first mention of a particular currency should use its full, unambiguous signifier (e.g. {{xt|A$52}}), with subsequent references using just the appropriate symbol (e.g. {{xt|$88}}), unless this would be unclear. {{em|Exceptions:}}
+
* In general, the first mention of a particular currency should use its full, unambiguous signifier (e.g. {{xt|A$52}}), with subsequent references using just the appropriate symbol (e.g. {{xt|$88}}), unless this would be unclear. ''Exceptions:''
:* In an article referring to multiple currencies represented by the same symbol (e.g. the dollars of the US, Canada, Australia, New Zealand, and other countries{{snd}}{{crossref|see {{section link|Currency symbols|dollar variants}}}}) use the full signifier (e.g. {{xt|US$}}, {{xt|A$}}) each time, except (possibly) where a particular context makes this both unnecessary and undesirable.
+
:* In an article referring to multiple currencies represented by the same symbol (e.g. the dollars of the US, Canada, Australia, New Zealand, and other countries - ''see [[Wikipedia:Currency symbols#dollar variants|Wikipedia:Dollar variants'') use the full signifier (e.g. {{xt|US$}}, {{xt|A$}}) each time, except (possibly) where a particular context makes this both unnecessary and undesirable.
 
:* In articles entirely on EU-, UK- and/or US-related topics, all occurrences may be shortened ({{xt|&euro;26}}, {{xt|&pound;22}} or {{xt|$34}}), unless this would be unclear.
 
:* In articles entirely on EU-, UK- and/or US-related topics, all occurrences may be shortened ({{xt|&euro;26}}, {{xt|&pound;22}} or {{xt|$34}}), unless this would be unclear.
* The [[pound sterling]] is represented by the {{xt|&pound;}} symbol, with one horizontal bar. The double-barred {{!xt|&#8356;}} symbol is ambiguous, as it has also been used for the [[Italian lira]] and other currencies. For non-British currencies that use pounds or a pound symbol (e.g. the [[Irish pound]], IR&pound;) use the symbol conventionally preferred for that currency.<!-- If no modern currency still uses the ₤ symbol, the developers should be asked to remove it from the edit tool box to prevent its misuse. -->
+
* The [[Wikipedia:Pound sterling|pound sterling]] is represented by the {{xt|&pound;}} symbol, with one horizontal bar. The double-barred {{!xt|&#8356;}} symbol is ambiguous, as it has also been used for the [[Wikipedia:Italian lira|Italian lira]] and other currencies. For non-British currencies that use pounds or a pound symbol (e.g. the [[Wikipedia:Irish pound|Irish pound]], IR&pound;) use the symbol conventionally preferred for that currency.
* If there is no common English abbreviation or symbol, follow the [[ISO 4217]] standard. {{crossref|See also [[List of circulating currencies]].}}
+
* If there is no common English abbreviation or symbol, follow the [[Wikipedia:ISO 4217|ISO 4217]] standard. ''See also [[Wikipedia:List of circulating currencies|List of circulating currencies]].''
  
==={{Anchor|Formatting of monetary values}}Formatting===
+
===Formatting===
{{Anchor|Format}}<!--Old, imprecise heading, may be linked to.-->
+
 
* A period (full stop, <code>.</code>) is used as the decimal point{{snd}}never a comma ({{xt|$6.57}}, not {{!xt|$6,57}}).
+
* A period (full stop, <code>.</code>) is used as the decimal point - never a comma ({{xt|$6.57}}, not {{!xt|$6,57}}).
* {{crossref|For the grouping of digits (e.g. {{xt|&pound;1,234,567}}) see {{section link||Grouping of digits}}, above.}}
+
* ''For the grouping of digits (e.g. {{xt|&pound;1,234,567}}) see {{section link||Grouping of digits}}, above.''
* Do not place a currency symbol {{em|after}} the accompanying numeric figures (e.g. {{!xt|123$}}, {{!xt|123&pound;}}, {{!xt|123&euro;}}) unless that is the normal convention for that symbol when writing in English: {{xt|smaller British coins include 1p, 2p, and 5p denominations}}. Never use forms such as {{!xt|$US123}} or {{!xt|$123 (US)}}.
+
* Do not place a currency symbol ''after'' the accompanying numeric figures (e.g. {{!xt|123$}}, {{!xt|123&pound;}}, {{!xt|123&euro;}}) unless that is the normal convention for that symbol when writing in English: {{xt|smaller British coins include 1p, 2p, and 5p denominations}}. Never use forms such as {{!xt|$US123}} or {{!xt|$123 (US)}}.
* Currency abbreviations that come before the numeric value are {{em|unspaced}} if they consist of a nonalphabetic symbol only, or end in a symbol ({{xt|&pound;123}};{{nbsp}}{{nbsp}} {{xt|&euro;123}}); but {{em|spaced}} if alphabetic ({{xt|R{{nbsp}}75}}).
+
* Currency abbreviations that come before the numeric value are ''unspaced'' if they consist of a nonalphabetic symbol only, or end in a symbol ({{xt|&pound;123}};{{nbsp}}{{nbsp}} {{xt|&euro;123}}); but ''spaced''
 +
if alphabetic ({{xt|R{{nbsp}}75}}).
 
* Ranges should be expressed giving the currency signifier just once: {{xt|$250{{ndash}}300}}, not {{!xt|$250{{ndash}}$300}}.
 
* Ranges should be expressed giving the currency signifier just once: {{xt|$250{{ndash}}300}}, not {{!xt|$250{{ndash}}$300}}.
 
* {{xt|million}} and {{xt|billion}} should be spelled out on first use, and (optionally) abbreviated {{xt|M}} or {{xt|bn}} (both unspaced) thereafter: {{xt|She received &pound;70 million and her son &pound;10M}}; {{xt|the school's share was $250{{ndash}}300 million, and the charity's $400{{ndash}}450M}}.
 
* {{xt|million}} and {{xt|billion}} should be spelled out on first use, and (optionally) abbreviated {{xt|M}} or {{xt|bn}} (both unspaced) thereafter: {{xt|She received &pound;70 million and her son &pound;10M}}; {{xt|the school's share was $250{{ndash}}300 million, and the charity's $400{{ndash}}450M}}.
 
* In general, a currency symbol should be accompanied by a numeric amount e.g. not {{!xt|He converted his US$ to A$}} but {{xt|He converted his US dollars to Australian dollars}} or {{xt|He exchanged the US$100 note for Australian dollars}}.
 
* In general, a currency symbol should be accompanied by a numeric amount e.g. not {{!xt|He converted his US$ to A$}} but {{xt|He converted his US dollars to Australian dollars}} or {{xt|He exchanged the US$100 note for Australian dollars}}.
:* Exceptions may occur in tables and infoboxes where space is limited e.g. {{xt|Currencies accepted for deposit: [[United States dollar|US$]], [[Swiss franc|SFr]], [[British pound|GB&pound;]], [[Euro|&euro;]]}}. It may be appropriate to wikilink such uses, or add an explanatory note.
+
:* Exceptions may occur in tables and infoboxes where space is limited e.g. {{xt|Currencies accepted for deposit: [[Wikipedia:United States dollar|US$]], [[Wikipedia:Swiss franc|SFr]], [[Wikipedia:British pound|GB&pound;]], [[Wikipedia:Euro|&euro;]]}}. It may be appropriate to wikilink such uses, or add an explanatory note.
  
 
===Conversions===
 
===Conversions===
* Conversions of {{em|less-familiar currencies}} may be provided in terms of more familiar currencies{{snd}}such as the US dollar, euro or pound sterling{{snd}}using an appropriate rate (which is often {{em|not}} the current exchange rate). Conversions should be in parentheses after the original currency, rounding to avoid [[false precision]] (two significant digits is usually sufficient, as most exchange rates fluctuate significantly), with at least the year given as a rough point of conversion rate reference; e.g. {{xt|Since 2001 the grant has been 10,000,000 [[Swedish krona|Swedish kronor]] ($1.4M, &euro;1.0M, or &pound;800k {{as of|2009|08|lc=on}})}}, not {{!xt|($1,390,570, &euro;971,673 or &pound;848,646)}}.<!-- Is "800k" really acceptable? -->
+
* Conversions of ''less-familiar currencies'' may be provided in terms of more familiar currencies - such as the US dollar, euro or pound sterling - using an appropriate rate (which is often ''not'' the current exchange rate). Conversions should be in parentheses after the original currency, rounding to avoid [[Wikipedia:False precision|false precision]] (two significant digits is usually sufficient, as most exchange rates fluctuate significantly), with at least the year given as a rough point of conversion rate reference; e.g. {{xt|Since 2001 the grant has been 10,000,000 [[Wikipedia:Swedish krona|Swedish kronor]] ($1.4M, &euro;1.0M, or &pound;800k, not {{!xt|($1,390,570, &euro;971,673 or &pound;848,646)}}.
* For {{em|obsolete currencies}}, provide an equivalent (formatted as a conversion) if possible, in the modern replacement currency (e.g. decimal pounds for historical pre-decimal pounds-and-shillings), or a US-dollar equivalent where there is no modern equivalent.
+
* For ''obsolete currencies'', provide an equivalent (formatted as a conversion) if possible, in the modern replacement currency (e.g. decimal pounds for historical pre-decimal pounds-and-shillings), or a US-dollar equivalent where there is no modern equivalent.
* In some cases it may be appropriate to provide a conversion accounting for inflation or deflation over time. {{crossref|See {{tlx|Inflation}} and {{tlx|Inflation-fn}}.}}
+
* In some cases it may be appropriate to provide a conversion accounting for inflation or deflation over time.
 +
 
 +
==Common mathematical symbols==
  
==<span id="Minus sign"></span>Common mathematical symbols==
 
{{shortcut|WP:COMMONMATH||MOS:MINUS}}
 
{{See also|Wikipedia:Manual of Style/Mathematics}}
 
 
* The ''Insert'' menu below the editing window gives a more complete list of math symbols, and allows symbols to be inserted without the HTML encoding (e.g. <code>&amp;divide;</code>) shown here.
 
* The ''Insert'' menu below the editing window gives a more complete list of math symbols, and allows symbols to be inserted without the HTML encoding (e.g. <code>&amp;divide;</code>) shown here.
* Spaces are placed to left and right when a symbol is used {{nobr|[[binary operation|with two operands]]}}, but no space is used when {{nobr|[[unary operation |there is one operand]]}}.
+
* Spaces are placed to left and right when a symbol is used [[Wikipedia:binary operation|with two operands]]}}, but no space is used when [[Wikipedia:unary operation |there is one operand]]}}.
* Use {{tlx|var}} or {{tag|var}} for variable names: <code><nowiki>{{var|base}} + {{var|ht}}</nowiki></code> and <code><nowiki><var>base</var> + <var>ht</var></nowiki></code> both produce {{var|base}} + {{var|ht}}.
+
* Use {{tag|var}} for variable names: <code><nowiki><var>base</var> + <var>ht</var></nowiki></code> produces <var>base</var> + <var>ht</var>.
* The {{tlx|nbsp}} and {{tlx|nowrap}} templates may be used to prevent awkward linebreaks.
+
* The {{tl|nbsp}} template may be used to prevent awkward linebreaks.
  
{{clear right}}
 
 
{|class="wikitable" style="align: center; text-align: center;"
 
{|class="wikitable" style="align: center; text-align: center;"
 
|+Common mathematical symbols
 
|+Common mathematical symbols
Line 1,043: Line 679:
 
! Comments
 
! Comments
 
|-
 
|-
| rowspan=2| [[Plus sign|Plus /<br />positive]]
+
| rowspan=2| [[Wikipedia:Plus sign|Plus /<br />positive]]
| {{var|x}} + {{var|y}}
+
| <var>x</var> + <var>y</var>
| <code>{{var|x}} + {{var|y}}</code>
+
| <code><nowiki><nowiki><var>x</var> + <var>y</var></nowiki></nowiki></code>
 
| rowspan=2|
 
| rowspan=2|
 
|-
 
|-
| +{{var|y}}
+
| +<var>y</var>
| <code>+{{var|y}}</code>
+
| <code><nowiki><nowiki>+<var>y</var></nowiki></nowiki></code>
 
|-
 
|-
| rowspan=2|[[Minus sign|Minus /<br />negative]]
+
| rowspan=2|[[Wikipedia:Minus sign|Minus /<br />negative]]
| {{var|x}} &minus; {{var|y}}
+
| <var>x</var> &minus; <var>y</var>
| <code>{{var|x}} &amp;minus; {{var|y}}</code>
+
| <code><nowiki><var>x</var> &amp;minus; <var>y</var></nowiki></code>
| rowspan=2|Do not use hyphen ({{!xt|<code>-</code>}}) or dashes ({{!xt|{{tlx|ndash}}}} {{nobr|or {{!xt|{{tlx|mdash}}}}).}}
+
| rowspan=2|Do not use hyphen ({{!xt|<code><nowiki>-</nowiki></code>}}) or dashes (&ndash;, {{!xt|{{tl|ndash}}}}, or {{!xt|&mdash;}}).
 
|-
 
|-
| &minus;{{var|y}}
+
| &minus;<var>y</var>
| <code>&amp;minus;{{var|y}}</code>
+
| <code><nowiki>&amp;minus;<var>y</var></nowiki></code>
 
|-
 
|-
|  rowspan=2| [[Plus-minus sign|Plus-minus /<br />minus-plus]]
+
|  rowspan=2| [[Wikipedia:Plus-minus sign|Plus-minus /<br />minus-plus]]
 
| 41.5 &plusmn; 0.3
 
| 41.5 &plusmn; 0.3
| <code>41.5 &amp;plusmn; 0.3</code>
+
| <code><nowiki>41.5 &amp;plusmn; 0.3</nowiki></code>
 
| rowspan=2|
 
| rowspan=2|
 
|-
 
|-
| {{nobr|1= &minus;(&plusmn;{{var|a}}) = &#8723;{{var|a}} }}
+
| &minus;(&plusmn;<var>a</var>) = &#8723;<var>a</var> }}
| {{nobr|1= <code>&amp;minus;(&amp;plusmn;{{var|a}}) = &amp;#8723;{{var|a}}</code> }}
+
| <code><nowiki>&amp;minus;(&amp;plusmn;<var>a</var>) = &amp;#8723;<var>a</var></nowiki></code> }}
 
|-
 
|-
| [[Multiplication sign|Multiplication]],<br />cross
+
| [[Wikipedia:Multiplication sign|Multiplication]],<br />cross
| {{var|x}} &times; {{var|y}}
+
| <var>x</var> &times; <var>y</var>
| <code>{{var|x}} &amp;times; {{var|y}}</code>  
+
| <code><nowiki><var>x</var> &amp;times; <var>y</var></nowiki></code>  
| Do not use the letter {{!xt|x}} to indicate multiplication. However, an {{em|unspaced}} {{xt|x}} may be used as a substitute for "by" in common terms such as [[4x4|{{xt|4x4}}]].  
+
| Do not use the letter {{!xt|x}} to indicate multiplication. However, an ''unspaced'' {{xt|x}} may be used as a substitute for "by" in common terms such as [[Wikipedia:4x4|{{xt|4x4}}]].  
 
|-
 
|-
| [[Division sign|Division]], obelus
+
| [[Wikipedia:Division sign|Division]], obelus
| {{var|x}} &divide; {{var|y}}
+
| <var>x</var> &divide; <var>y</var>
| <code>{{var|x}} &amp;divide; {{var|y}}</code>
+
| <code><nowiki><var>x</var> &amp;divide; <var>y</var></nowiki></code>
 
| rowspan=8|
 
| rowspan=8|
 
|-
 
|-
| [[Equal sign|Equal / equals]]
+
| [[Wikipedia:Equal sign|Equal / equals]]
| {{var|x}} = {{var|y}}
+
| <var>x</var> = <var>y</var>
| <code>{{var|x}} = {{var|y}}</code>
+
| <code><nowiki><var>x</var> = <var>y</var></nowiki></code>
 
|-
 
|-
| [[Not equal sign|Not equal]]
+
| [[Wikipedia:Not equal sign|Not equal]]
| {{var|x}} &ne; {{var|y}}
+
| <var>x</var> &ne; <var>y</var>
| <code>{{var|x}} &amp;ne; {{var|y}}</code>
+
| <code><nowiki><var>x</var> &amp;ne; <var>y</var></nowiki></code>
 
|-
 
|-
| [[Approximate sign|Approx. equal]]
+
| [[Wikipedia:Approximate sign|Approx. equal]]
| {{pi}} &asymp; 3.14
+
| &#960; &asymp; 3.14
| <code>{{tlx|pi}} &amp;asymp; 3.14</code><!-- should the pi be italic? -->
+
| <code><nowiki>{{tlx|pi}} &amp;asymp; 3.14</nowiki></code><!-- should the pi be italic? -->
 
|-
 
|-
| [[Less than sign|Less than]]
+
| [[Wikipedia:Less than sign|Less than]]
| {{var|x}} &lt; {{var|y}}
+
| <var>x</var> &lt; <var>y</var>
| <code>{{var|x}} &amp;lt; {{var|y}}</code>
+
| <code><nowiki><var>x</var> &amp;lt; <var>y</var></nowiki></code>
 
|-
 
|-
| [[Less than or equal to|Less or equal]]
+
| [[Wikipedia:Less than or equal to|Less or equal]]
| {{var|x}} &le; {{var|y}}
+
| <var>x</var> &le; <var>y</var>
| <code>{{var|x}} &amp;le; {{var|y}}</code>
+
| <code><nowiki><var>x</var> &amp;le; <var>y</var></nowiki></code>
 
|-
 
|-
| [[Greater than sign|Greater than]]
+
| [[Wikipedia:Greater than sign|Greater than]]
| {{var|x}} &gt; {{var|y}}
+
| <var>x</var> &gt; <var>y</var>
| <code>{{var|x}} &amp;gt; {{var|y}}</code>
+
| <code><nowiki><var>x</var> &amp;gt; <var>y</var></nowiki></code>
 
|-
 
|-
| [[Greater than or equal to|Greater or equal]]
+
| [[Wikipedia:Greater than or equal to|Greater or equal]]
| {{var|x}} &ge; {{var|y}}
+
| <var>x</var> &ge; <var>y</var>
| <code>{{var|x}} &amp;ge; {{var|y}}</code>
+
| <code><nowiki><var>x</var> &amp;ge; <var>y</var></nowiki></code>
 
|}
 
|}
 
==Geographical coordinates==
 
<div style="float:right; width:100px;">{{Shortcut|MOS:COORDS|WP:COORDINATES}}</div>
 
 
:{{crossref|For draft guidance on, and examples of, coordinates for linear features, see [[Wikipedia:WikiProject Geographical coordinates/Linear]].}}
 
 
:'''Quick guide''':
 
 
{{coord how-to}}
 
 
[[Geographical coordinates]] on Earth should be entered using a template to standardise the format and to provide a link to maps of the coordinates. As long as the templates are adhered to, a robot performs the functions automatically.
 
 
First, [[Wikipedia:Obtaining geographic coordinates|obtain the coordinates]]. Avoid [[Wikipedia:WikiProject Geographical coordinates#Precision|excessive precision]].
 
 
Two types of template are available:
 
* {{tlx|coord}} offers users a choice of display format through [[Help:User style|user style]]s, emits a [[Geo microformat]], and is recognised (in the {{em|title}} position) by the "nearby" feature of  Wikipedia's mobile apps and by external service providers such as Google Maps and Google Earth, and Yahoo.
 
* Infoboxes such as {{tlx|Infobox settlement}}, which automatically emit {{tlx|Coord}}.
 
 
The following formats are available.
 
* For degrees only (including decimal values): {{tlc|coord|2={{var|dd}}|3={{var|N/S}}|4={{var|dd}}|5={{var|E/W}}}}
 
* For degrees/minutes: {{tlc|coord|2={{var|dd}}|3={{var|mm}}|4={{var|N/S}}|5={{var|dd}}|6={{var|mm}}|7={{var|E/W}}}}
 
* For degrees/minutes/seconds: {{tlc|coord|2={{var|dd}}|3={{var|mm}}|4={{var|ss}}|5={{var|N/S}}|6={{var|dd}}|7={{var|mm}}|8={{var|ss}}|9={{var|E/W}}}}
 
 
where:
 
* {{var|dd}}, {{var|mm}}, {{var|ss}} are the degrees, minutes and seconds, respectively;
 
* {{var|N/S}} is either <kbd>N</kbd> for northern or <kbd>S</kbd> for southern [[latitude]]s;
 
* {{var|E/W}} is either <kbd>E</kbd> for eastern or <kbd>W</kbd> for western [[longitude]]s;
 
* negative values may be used in lieu of <kbd>S</kbd> and <kbd>W</kbd> to denote Southern and Western [[Hemisphere of the Earth|Hemispheres]]
 
 
For example:
 
 
For the city of [[Oslo]], located at 59° 55&prime; N, 10° 44&prime; E:
 
: <code><nowiki>{{coord|59|55|N|10|44|E}}</nowiki></code>{{snd}}which becomes {{coord|59|55|N|10|44|E}}
 
 
For a country, like [[Botswana]], less precision is appropriate:
 
: <code><nowiki>{{coord|22|S|24|E}}</nowiki></code>{{snd}}which becomes {{coord|22|S|24|E}}
 
 
Higher levels of precision are obtained by using seconds:
 
: <code><nowiki>{{coord|33|56|24|N|118|24|00|W}}</nowiki></code>{{snd}}which becomes {{coord|33|56|24|N|118|24|00|W}}
 
 
Coordinates can be entered as decimal values
 
: <code><nowiki>{{coord|33.94|S|118.40|W}}</nowiki></code>{{snd}}which becomes {{coord|33.94|S|118.40|W}}
 
 
Increasing or decreasing the number of decimal places controls the precision. Trailing zeros should be used as needed to ensure that both values have the same level of precision.
 
 
[[London Heathrow Airport]], [[Amsterdam]], [[Jan Mayen]] and [[Mount Baker]] are examples of articles that contain geographical coordinates.
 
 
Generally, the larger the object being mapped, the {{em|less precise}} the coordinates should be. For example, if just giving the location of a city, precision greater than 100{{nbsp}}meters is not needed unless specifying a particular point in the city, for example the central administrative building. Specific buildings or other objects of similar size would justify precisions down to 10{{nbsp}}meters or even one meter in some cases (1′′ ~15{{nbsp}}m to 30{{nbsp}}m, 0.0001° ~5.6{{nbsp}}m to 10{{nbsp}}m).
 
 
The final field, following the E/W, is available for attributes such as <code>type:</code>, <code>region:<code>, or <code>scale:<code> {{crossref|(the codes are documented at [[Template:Coord/doc#Coordinate parameters]])}}.
 
 
When adding coordinates, please remove the {{tlx|coord missing}} tag from the article, if present.
 
 
{{Crossref|For more information, see [[Wikipedia:WikiProject Geographical coordinates|the geographical coordinates WikiProject]].}}
 
 
Templates other than {{tlx|coord}} should use the following variable names for coordinates: {{var|lat_d}}, {{var|lat_m}}, {{var|lat_s}}, {{var|lat_NS}}, {{var|long_d}}, {{var|long_m}}, {{var|long_s}}, {{var|long_EW}}.
 
  
 
==See also==
 
==See also==
* [[Wikipedia:Naming conventions (numbers and dates)]]
+
* [[Wikipedia:Wikipedia:Naming conventions (numbers and dates)|Wikipedia:Naming conventions (numbers and dates)]]
* [[Wikipedia:Date formattings]]
+
* [[Wikipedia:Wikipedia:Date formatting|Wikipedia:Date formattings]]
* [[m:Help:Date formatting feature]] at Meta
+
* [https://meta.wikimedia.org/wiki/Help:Date_formatting_and_linking Help:Date formatting and linking] at Meta-Wiki
* {{section link|m:Help:Calculation|Displaying numbers and numeric expressions}} at Meta
+
* [https://meta.wikimedia.org/wiki/Help:Calculation#Displaying_numbers_and_numeric_expressions Help:Displaying numbers and numeric expressions] at Meta-Wiki
  
 
==Notes and references==
 
==Notes and references==

Latest revision as of 19:31, 5 December 2021

This page is a part of the UniWiki's Manual of Style. It is a general guideline intended to harmonize article style across the UniWiki, though it is best treated with common sense, and exceptions may apply. Any substantive edit to this page should be approved by the Wiki Manager. When in doubt, discuss first on the talk page.

This page guides the presentation of numbers, dates, times, measurements, currencies and similar material in articles. Its aim is to promote clarity and cohesion; this is especially important within an article. The goal is to make the whole UniWiki easier and more intuitive to use.

Where this manual provides options, consistency should be maintained within an article unless there is a good reason to do otherwise. If discussion cannot determine which style to use in an article, defer to the style used by the first major contributor.

General notes

Quotations, titles, etc.

Quotations, titles of books and articles, and similar "imported" text should be faithfully reproduced, even if they employ formats or units inconsistent with these guidelines or with other formats in the same article. If necessary, clarify via [bracketed interpolation], article text, or footnotes.

  • It is acceptable to change other date formats in the same article to provide consistency, so long as those changes would otherwise be acceptable.

Non-breaking spaces

Guidance on the use of non-breaking spaces ("hard spaces") – &nbsp;, &thinsp; – is given in some sections below. Not all situations in which hard spaces may be appropriate are described. For further information, see Wikipedia:Manual of Style § Controlling line breaks and Wikipedia:Line-break handling.

Chronological items

Statements likely to become outdated

See also: UniWiki:Manual of Style/Words to watch#Relative time references, and Wikipedia:As of

Except on pages updated regularly, terms such as now, currently, to date, so far, soon, and recently should usually be avoided in favor of phrases such as during the 1990s, since 2010, and in August 1969. For current and future events, use phrases like as of November 2024 or since the beginning of 2024 to signal the time-dependence of the information.

However, do not replace since the beginning of 2005 with as of 2005 because some information (the beginning of 2005) would be lost.

Relative-time expressions are acceptable for very long periods, such as geological epochs: Humans diverged from other primates long ago, but only recently developed state legislatures.

Time of day

Context determines whether the 12- or 24-hour clock is used; in both, colons separate hours, minutes and seconds (e.g. 1:38:09 pm or 13:38:09).

  • 12-hour clock times end with dotted or undotted lower-case a.m. or p.m., or xtn|am or pm, preceded by a non-breaking space, e.g. 2:30 p.m. or 2:30 pm (markup: 2:30&nbsp;p.m. or 2:30&nbsp;pm), not 2:30p.m. or 2:30pm. Hours should not have a leading zero (e.g. 2:30 p.m., not 02:30 p.m.). Usually, use noon and midnight rather than 12 pm and 12 am; whether "midnight" refers to the start or the end of a date should be explicitly specified unless clear from the context.
  • 24-hour clock times have no a.m., p.m., noon or midnight suffix. Hours under 10 should have a leading zero (e.g. 08:15). The time 00:00 refers to midnight at the start of a date, 12:00 to noon, and 24:00 to midnight at the end of a date, but 24 should not be used for the first hour of the next day (e.g. use 00:10 for ten minutes after midnight, not 24:10).

The numerical elements of times-of-day are figures (12:45 p.m.) rather than words (twelve forty-five p.m.) though conventional terms such as noon and midnight are acceptable (taking care, with the latter, to avoid possible date ambiguity in constructions such as midnight on July 17).

Time zones

Give dates and times appropriate to the time zone where an event took place. For example, the date of the attack on Pearl Harbor should be December 7, 1941 (Hawaii time/​date). Give priority to the place at which the event had its most significant effects; for example, if a hacker based in China attacked a Pentagon computer in the US, use the time zone for the Pentagon, where the attack had its effect. In some cases the best solution may be to add the date and time in Coordinated Universal Time (UTC). For example:

  •   8 p.m. Eastern Standard Time on January 15, 2001 (01:00 UTC, January 16)

Alternatively, include just the UTC offset:

  •  21:00 British Summer Time (UTC+1) on 27 July 2012

Rarely, the time zone in which a historical event took place has since changed; for example, China to 1949 was divided into five time zones, whereas all of modern China is UTC+8. Similarly, the term "UTC" is not appropriate for dates before this system was adopted in 1960; Universal Time (UT) is the appropriate term for the mean time at the prime meridian (Greenwich) when it is unnecessary to specify the precise definition of the time scale. Be sure to show the UTC or offset appropriate to the clock time in use at the time of the event, not the modern time zone, if they differ.

Dates, months and years

Formats

Acceptable date formats
General use Only where brevity is helpful
(refs, tables, infoboxes, etc.)
Comments
2 August 2001 2 Aug 2001
August 2, 2001 Aug 2, 2001 A comma follows the year unless followed by other punctuation:[1]
* The weather on March 12, 2005, was clear and warm
* Everyone remembers July 21, 1969 - when man first landed on the Moon
2 August 2 Aug Omit year only where there is no risk of ambiguity:
* The 2012 London Olympics ran from 25 July to 12 August
* January 1 is New Year's Day
August 2 Aug 2
No equivalent for general use 2001-08-02 Use yyyy-mm-dd format only with Gregorian dates from 1583 onward.[2]
August 2001 Aug 2001
Unacceptable date formats (except in external titles and quotes)
Unacceptable Acceptable Comments
Aug. 2 Aug 2 Do not add a dot to the day or to an abbreviated month
9. June 9 June or June 9
9 june
june 9
Months are capitalized
9th June
June 9th
the 9th of June
Do not use ordinals (1st, 2nd, 3rd, etc.)
09 June
June 09
Do not "zero-pad" month or day, except in all-numeric (yyyy-mm-dd) format
2007-4-15 2007-04-15
2007/04/15 Do not use separators other than hyphen
07-04-15 Do not abbreviate year to two digits
15-04-2007
04-15-2007
Do not use dd-mm-yyyy, mm-dd-yyyy or yyyy-dd-mm formats, as they are ambiguous for some dates[3]
7/2001
7-2001
07-2001
2001-07
2001 July
July of 2001
July 2001 Do not use these formats.
July, 2001
No comma between month and year
3 July, 2001 3 July 2001
July 3 2001 July 3, 2001 Comma required between day and year
the '97 elections
the 97 elections
the 1997 elections Do not abbreviate year
Two thousand one 2001 Years and days of the month are not normally written in words
the first of May
May the first
May 1 or 1 May
June 0622 June 622 Do not zero-pad years
sold in the year 1995 sold in 1995 Use "in the year" only where needed for clarity (About 1800 ships arrived in the year 1801)
Consistency

Dates in article body text should all use the same format: She fell ill on 25 June 2005 and died on 28 June, but not She fell ill on 25 June 2005 and died on June 28.

Retaining existing format
See also: UniWiki:Manual of Style#Retaining existing styles
  • If an article has evolved using predominantly one format, the whole article should conform to it, unless there are reasons for changing it based on strong national ties to the topic or consensus on the article's talk page.
  • The date format chosen by the first major contributor in the early stages of an article should continue to be used, unless there is reason to change it based on strong national ties to the topic or consensus on the article's talk page.
  • Where an article has shown no clear sign of which format is used, the first person to insert a date is equivalent to "the first major contributor".

Gregorian and New Eden calendars

Dates on the UniWiki must be given in the appropriate calendar based on the context of the date or event they are associated with. A date can be given in the Gregorian calendar, the New Eden calendar, or both, as described below. For example, an article on the early Amarr Empire will only give dates in the New Eden calendar, while an article about the Purity of the Throne event may give dates in both calendars.

  • Real-world events are dated using the Gregorian calendar.
  • In-game events that correspond to real-world dates (such as the Yoiul Festival 2016) or that are the result of player actions are dated using the New Eden calendar when discussing the event in an in-universe context, and using the Gregorian calendar when discussing the event in a real-world or meta context.
  • All other in-game events or lore concepts are dated using the New Eden calendar.

Ranges

  • Use a dash, or a word such as from or between, but not both: from 1881 to 1886 (not from 1881–1886);  between June 1 and July 3 (not between June 1 - July 3)
  • A simple year–year range is written using an en dash (&ndash;) not a hyphen or slash; this dash is usually unspaced (that is, with no space on either side); and the range's end year is usually given in full:
  •   1881–18861881–1992 (not 1881–861881 - 1992)
Markup: 1881{{ndash}}1886 or 1881&ndash;1886
  • Two-digit ending years (1881–82, but never 1881–882 or 1881–2) may be used in the case of two consecutive years; in infoboxes and tables where space is limited (using a single format consistently in any given table column); or in certain topic areas if there is a very good reason, such as matching the established convention of reliable sources.
  • The slash notation (2005/2006) may be used to signify a fiscal year or other special period, if that convention is used in reliable sources.
  • Other "simple" ranges use an unspaced en dash as well:
  • day–day: 5–7 January 1979January 5–7, 1979elections were held March 5–8
  • month–month: the 1940 peak period was May–Julythe peak period was May–July 1940;  (but the peak period was May 1940 - July 1940 uses a spaced en dash; see below.
  • If at least one of the items on either side of the en dash contains a space, then a spaced en dash ({{snd}}) is used:
  • between specific dates in different months: They travelled June 3 - August 18, 1952They travelled 3 June - 18 August 1952
  • between dates in different years:
Charles Robert Darwin (12 February 1809 - 19 April 1882) was an English naturalist ...
Markup: 12{{nbsp}}February 1809{{snd}}19{{nbsp}}April 1882 or 12&nbsp;February 1809&nbsp;&ndash; 19&nbsp;April 1882
Abraham Lincoln (February 12, 1809 - April 15, 1865) was the 16th President of ...
  • between months in different years: The exception was in force August 1892 - January 1903The Ghent Incursion (March 1822 - January 1, 1823) was ended by the New Year's Treaty
Markup: March 1822{{snd}}January{{nbsp}}1, 1823 or March 1822&nbsp;&ndash; January&nbsp;1, 1823
  • Constructions such as 1982–present (with unspaced ndash), January 1, 2011 - present (spaced ndash), or January 2011 - present (spaced ndash) may be used where appropriate, but other constructions may be more appropriate in prose (see § Statements likely to become outdated). In tables and infoboxes where space is limited, pres. may be used (1982–pres.). Do not use incomplete-looking constructions such as 1982– and 1982–... .
  • For a person still living: Serena Williams (born September 26, 1981) is a ..., not (September 26, 1981 - ) or (born on September 26, 1981).
Do not use * to indicate born; use b. only where space is limited e.g. tables and infoboxes; use either born or b. consistently in any given table column.
  • Where birthdate is unknown: John Smith (died May 1, 1622) ... or John Smith (died 1622) ...
Do not use to indicate died; use d. only where space is limited, with consistency within any given table column.
  • An overnight period may be expressed using a slash between two contiguous dates: the night raids of 30/31 May 1942 or raids of 31 May / 1 June 1942.
Or use an en dash: (unspaced) raids of 30–31 May 1942;  (spaced) raids of 31 May - 1 June 1942.

Uncertain, incomplete, or approximate dates

  • To indicate "around", "approximately", or "about", the use of the spaced, unitalicised form c. 1291 is preferred over circa, ca, ca., approximately, or approx.:
  •   At the birth of Roger Bacon (c. 1214) ...
  • Where both endpoints of a range are approximate, c. should appear before each date:
  •   Dionysius Exiguus (c. 470 - c. 540) ... (not Dionysius Exiguus (c. 470 - 540) ...)
  •   Rameses III (reigned c. 1180 – c. 1150 BCE) ... (not Rameses III (reigned c. 1180 - 1150 BCE) ...)
  • When a date is known to be either of two years (e.g. from a regnal or AH year conversion, or a known age at death):
  •   Anne Smith (born 1912 or 1913; died 2013) ...
  • Other forms of uncertainty should be expressed in words, either in article text or in a footnote: April 14, 1224 (unattested date). Do not use a question mark (1291?), because it fails to communicate the nature of the uncertainty.
  • Ranges in which c., after, fl. or similar forms appear—whether on one or both sides—employ a spaced endash ( - ) and ideally a nonbreaking space should follow very short modifiers such as c. and fl.. Markup: 1896 - after 1954

Other

Days of the week

  • Days of the week are capitalized (Sunday, Wednesday).

Seasons

  • Seasons are uncapitalized (a hot summer) except when personified: Old Man Winter's bleak greys relent as Spring begins to show her colors.
  • All seasons used should refer to seasons in the northern hemisphere, as that is where CCP is located, and is thus the reference point for game development, patch releases, and other events.
    • In the rare case where an article references seasons in relation to a specific country or region not in the northern hemisphere, the appropriate season for that location may be used.

Numbers

Numbers as figures or words

See

also information on specific situations, elsewhere in this guideline.

Generally, in article text:

  • Integers from zero to nine are spelled out in words.
  • Integers greater than nine expressible in one or two words may be expressed either in numerals or in words (16 or sixteen, 84 or eighty-four, 200 or two hundred). Numbers between 21 and 99 are hyphenated (including when part of a larger number): fifty-six or fifty-six thousand but five hundred or five thousand.
  • Other numbers are given in numerals (3.75, 544) or in forms such as 21 million. Markup: 21{{nbsp}}million
  • "billion" and "trillion" are understood to represent their short-scale values of 109 (1,000,000,000) and 1012 (1,000,000,000,000), respectively. Keep this in mind when using material from non-English sources.
  • M (unspaced) or bn (unspaced) respectively may be used for "million" or "billion" after a number, when the word has been spelled out at the first occurrence (She received £70 million and her son £10M).
  • SI prefixes and symbols, such as mega- (M), giga- (G) and tera- (T), should be used only with units of measure as appropriate to the field, and not to express large quantities in other contexts (of the population of 1.3G people, 300 megadeaths would be expected).

Notes and exceptions:

  • In tables and infoboxes, quantities are expressed in figures (Years in office: 5); but numbers within a table's explanatory text and comments follow the general rule.
  • Numbers in mathematical formulae are never spelled out (3 < π < 22/7, not three < π < 22 sevenths).
  • Comparable quantities should be all spelled out or all in figures:
  •  five cats and thirty-two dogs, not five cats and 32 dogs
  •  86 men and 103 women, not eighty-six men and 103 women
  •  There were 3 winners and 206 losers, even though 3 would normally be given as three; or Three won and two hundred six lost (or two hundred and six in British English), even though two hundred six would normally be given as 206); but not There were three winners and 206 losers.
  • But adjacent quantities not comparable should usually be in different formats: twelve 90-minute volumes or 12 ninety-minute volumes, not 12 90-minute volumes or twelve ninety-minute volumes.
  • Avoid awkward juxtapositions: On February 25, 2011, twenty-one more were chosen, not On February 25, 2011, 21 more were chosen.
  • Personal ages are typically stated in figures (8-year-old child) except for large, approximate values (69-million-year-old fossil).
  • Sometimes figures and words carry different meanings; for example Every locker except one was searched implies there is a single exception (without specifying which), while Every locker except 1 was searched means that only locker number 1 was not searched.
  • Proper names, technical terms, and the like are never altered: Seven SamuraiThe Sixth Sense5 Channel StreetChannel 5Chanel No. 5Fourth EstateThe Third ManSecond Judicial DistrictFirst AmendmentZero Hour!Less Than Zero
  • Avoid beginning a sentence with figures:
  •   Not There were many matches. 23 ended in a draw,
      but There were many matches; 23 ended in a draw or There were many matches. Twenty-three ended in a draw.
  •   Not 1945 and 1950 saw crucial elections (nor Nineteen forty-five and 1950 saw crucial elections - because comparable numbers should be both written in words or both in figures) but The elections of 1945 and 1950 were crucial.
  • Exception: Where a proper name, technical term, etc., itself beginning with a numeral, opens the sentence (1-Naphthylamine is typically synthesized via the Feldenshlager–Glockenspiel process) although this can usually be avoided by rewording (Feldenshlager–Glockenspiel is the process typically used in the synthesis of 1-naphthylamine).

Ordinals

Singular versus plural

  • Nouns following simple fractions are singular (He took 14 dosenet change in score was −12 point32 dose).
  • Nouns following mixed numbers are plural (suicide victim knew even 112 doses could be fatalcontinued another 434 miles).
  • Nouns following the lone, unsigned digit 1 are singular, but those following other decimal numbers (i.e. base-10 numbers not involving fractions) are plural (increased 0.7 percentage points365.25 dayspaid 5 dollars per work hour, 1 dollar per travel hour, 0 dollars per standby hourincreased by 1 point but net change +1 pointsnet change −1 pointsnet change 1.0 points).
  • The same rules apply to numbers given in words (one doseone and one-half doseszero dollarsnet change negative one points).

Fractions and ratios

  • Spelled-out fractions are hyphenated: seven-eighths.
  • Where numerator and denominator can each be expressed in one word, a fraction is usually spelled out (e.g. a two-thirds majority;  moved one-quarter mile); use figures if a fraction appears with a symbol (e.g. 14 mi - markup: <sup>1</sup>&frasl;<sub>4</sub>&nbsp;mi, not a quarter of a mi or one-quarter mi).
  • Mixed numbers are usually given in figures, unspaced (not Fellini's film 12 or 8-12 but Fellini's film 812 - markup: 8<sup>1</sup>&frasl;<sub>2</sub>). In any case the integer and fractional parts should be consistent (not nine and 12).
  • Metric (SI) measurements generally use decimals, not fractions (5.25 mm, not 514 mm).
  • Do not use special characters such as "½" (deprecated markup: &frac12; or &#189;).
  • Ordinal suffixes such as -th should not be used with fractions expressed in figures (not each US state has 1/50th of the Senate's votes1/8th mile, but one-fiftieth of the Senate's votes1/8 mileone-eighth mile).
  • Dimensionless ratios (i.e. those not incorporating units) are given using numerals and a colon, or numbers-as-words and to: favored by a 3:1 ratio or a three-to-one ratio, but not a 3/1 ratio or a 3–1 ratio. Use a "spaced" colon when a decimal point is present (a 3.5 : 1 ratio - markup: a 3.5&nbsp;:&nbsp;1 ratio). Do not use the colon form where units are involved (dissolve using a 3 ml:1 g ratio)—instead see ratios section of table at § Unit names and symbols, below.

Decimals

  • A period/full point (.), never a comma, is used as the decimal point (6.57, not 6,57).
  • Numbers between −1 and +1 require a leading zero (0.02, not .02); exceptions are sporting performance averages (.430 batting average) and commonly used terms such as .22 caliber.
  • Indicate repeating digits with an overbar e.g. 14.31<span style="text-decoration:overline">28</span> gives 14.3128. (Consider explaining this notation on first use.) Do not write e.g. 14.31(28) because it resembles notations for § Uncertainty and rounding.

====Grouping

of digits====
  • Digits should be grouped and separated by commas, (never a period/full point).
Grouping with commas
  • Left of the decimal point, five or more digits are grouped into threes separated by commas (e.g.  12,200,  255,200 km,  8,274,527th,  186,400).
  • Numbers with exactly four digits left of the decimal point may optionally be grouped (either  1,250  or  1250), provided that this is consistent within each article.
  • When commas are used left of the decimal point, digits right of the decimal point are not grouped (i.e. should be given as an unbroken string).
  • Delimiting style should be consistent throughout a given article.
  • Either group the thousands in a four-digit number or do not, but not mixed use in the same article.
  • However, grouping by threes and fives may coexist.
  • An exception is made for four-digit page numbers or four-digit calendar years. These should never be grouped (not  sailed in 1,492,  though  dynasty collapsed around 10,400 BC).

Percentages

  • In the body of non-scientific/non-technical articles, percent (American English) or per cent (British English) are commonly used: 10 percent; ten percent; 4.5 per cent. Ranges are written ten to twelve per cent or ten to twelve percent, not ten–twelve per cent or ten to twelve %.
  • In the body of scientific/​technical articles, and in tables and infoboxes of any article, the symbol % (unspaced) is more common: 71%, not 71 % or three %. Ranges: 10–12%, not 10%–12% or 10 to 12%.
  • When expressing the difference between two percentages, do not confuse a percentage change with a change in percentage points.

Scientific notation

  • Scientific notation always has a single nonzero digit to the left of the point: not 60.22 × 1022, but 6.022 × 1023.
  • In a table column (or other presentation) in which all values can be expressed with a single power of 10, consider giving e.g.  × 107 once in the column header, and omitting it in the individual entries. (Markup: &nbsp;&times;&nbsp;10<sup>7</sup>)
  • The number of digits indicates the precision. For example, 5 × 103 means rounded to the nearest thousand; 5.0 × 103 to the nearest hundred; 5.00 × 103 to the nearest ten; and 5.000 × 103 to the nearest unit.

Uncertainty and rounding

  • Where explicit uncertainty information (such as a margin of error) is available and appropriate for inclusion, it may be written in various ways:
  •  (1.534 ± 0.035) × 1023 m
  •  12.34 m2 ± 5% (not used with scientific notation)
  •  1.604(48) × 10−4 J (equivalent to (1.604 ± 0.048) × 10−4 J)[4]
  •  Polls estimated Jones's share of the vote would be 55 percent, give or take about 3 percent
  • Where explicit uncertainty is unavailable (or is unimportant for the article's purposes) round to an appropriate number of significant digits; the precision presented should usually be conservative. Precise values (often given in sources for formal or matter-of-record reasons) should be used only where stable and appropriate to the context, or significant in themselves for some special reason.
  •   The speed of light is defined to be 299,792,458 m/s
but Particle velocities eventually reached almost two-thirds the 300-million-metre-per-second speed of light.
  •   The city's 1920 population was 10,000 (not population was 9,996 - an official figure unlikely to be accurate at full precision)
but The town was ineligible because its official census figure (9,996) fell short of the statutory minimum of ten thousand (unusual case in which the full-precision official population figure is helpful to readers)
  •   The accident killed 337 passengers and crew, and three airport workers (likely that accurate and precise figures were determined)
  •   At least 800 persons died in the ensuing mudslides (unlikely that any precise number can be accurate, even if an official figure is issued)
or Officials listed 835 deaths, but the Red Cross said dozens more may have gone unreported (in reporting conflicting information, give detail sufficient to make the contrast intelligible)
  •   The jury's award was $8.5 million ... (where the actual figure was $8,462,247.63) ... - reduced on appeal to $3,000,001 (one dollar in actual damages, the remainder in punitive damages)
  • The number of decimal places should be consistent within a list or context (The response rates were 41.0 and 47.4 percent, respectively, not 41 and 47.4 percent), unless different precisions are actually intended.
  • It may sometimes be appropriate to note the lack of uncertainty information, especially where such information is normally provided and necessary for full interpretation of the figures supplied.
  •   A local newspaper poll predicted 52 percent of the vote would go to Smith, but did not publish information on the uncertainty of this estimate
  • Avoid using "approximately", "about", and similar terms with figures that have merely been approximated or rounded in a normal and expected way, unless the reader might otherwise be misled.
  •   The tallest player was 6 feet 3 inches (not ... about 6 feet 3 inches - heights are conventionally reported only to the nearest inch, even though greater precision may be available in principle)
but The witness said the assailant was about 5 feet 8 inches tall ("about" because here the precise value is unknown, with substantial uncertainty)
  • The reader may be assumed to interpret large round numbers (100,000 troops) as approximations. Writing a quantity in words (one hundred thousand troops) can further emphasize its approximate nature.

Non-base-10 notations

  • In computer-related articles, use the prefix 0x for hexadecimal, 0 for octal, and 0b for binary, unless there is a strong reason to use some other notation.[5] Explain these prefixes in the article's introduction or on first use.
  • In all other articles, use <sub> to create subscripts: 1379, 2013. Markup: 137<sub>9</sub>, 201<sub>3</sub>
  • For bases above 10, use symbols conventional for that base (e.g. for base 16 use 0–9 and A–F.

Units of measurement

Unit choice and order

Quantities are typically expressed using an appropriate "primary unit", displayed first, followed, when appropriate, by a conversion in parentheses e.g. 200 kilometers (120 mi).

In all articles, the primary units chosen will be SI units, non-SI units officially accepted for use with the SI, or such other units as they appear in-game.

Unit names and symbols

Definitions:
  • Examples of unit names: foot, meter, kilometer.
  • Examples of unit symbols: ft, m, km.
  • Unit names and symbols should follow the practice of reliable sources.
  • In prose, unit names should be given in full if used only a few times, but symbols may be used when a unit (especially one with a long name) is used repeatedly, after spelling out the first use (e.g. Up to 15 kilograms of filler is used for a batch of 250 kg).
  • Exception: Certain units are generally represented by their symbols (e.g. °C rather than degrees Celsius) even on first use, though their unit names may be used for emphasis or clarity (automatic conversion of degrees Celsius to degrees Fahrenheit).
  • Where space is limited, such as in tables, infoboxes, parenthetical notes, and mathematical formulas, unit symbols are preferred.
  • Units unfamiliar to general readers should be presented as a name–symbol pair on first use, linking the unit name (Energies were originally 2.3 megaelectronvolts (MeV), but were eventually 6 MeV).
  • Ranges use unspaced en dash ({{ndash}}) if only one unit symbol is used at the end (e.g. 5.9–6.3 kg), and spaced en dash ({{snd}}) if two symbols are used (e.g. 3 μm - 1 mm); ranges
in prose may be specified using either unit symbol or unit names, and units may be stated either after both numerical values or after the last (e.g. from 5.9 to 6.3 kilograms, from 5.9 kilograms to 6.3 kilograms, from 5.9 to 6.3 kg and from 5.9 kg to 6.3 kg are all acceptable).
  • Length–width, length–width–height and similar dimensions may be separated by the multiplication sign (× or &times;) or the word by.
    • With the multiplication sign, each number should be followed by a unit name or symbol (if appropriate):
  •  1 m × 3 m × 6 m, not 1 × 3 × 6 m, (1 × 3 × 6) m nor 1 × 3 × 6 m3
  •  a metal plate 1 ft × 3 ft × 0.25 in
  •  a railroad easement 10 ft × 2.5 mi
  • With by, the unit need be given only once: 1 by 3 by 6 metres or 1 by 3 by 6 m
  • The unspaced letter x may be used in common terms such as 4x4.
General guidelines on unit names and symbols
Aspect Guideline Acceptable Unacceptable
Unit names and symbols Unit symbols are uncapi­tal­ized unless they are derived from a proper name, in which case the first letter (of the base unit symbol, not of any prefix) is capitalized.[6] 8 kg
100 kPa
8 Kg
100 kpa
Unit symbols are undotted. 38 cm of rope 38 cm. of rope
Unit names are given in lower case except: where any word would be capital­ized, or where otherwise specified in the SI brochure or this Manual of Style.
  • He walked several miles.
  • Miles of trenches were dug.
A Gallon equals 4 Quarts.
The spelling of certain unit names (some of which are listed in § Specific units, below) varies with the variety of English followed by the article.
Write unit names and symbols in upright (roman) type, except where emphasizing in context. 10 m
29 kilograms
10 m
29 kilograms
Thus each two-liter jug contained only two quarts.
Numeric values Do not spell out numbers before unit symbols ... 12 min twelve min
... but words or figures may be used with unit names.
  • twelve minutes
  • 12 minutes
Values with no accompanying unit are usually given in figures. Set the pointer to 5. Set the pointer to five.
Use a nonbreaking space ({{nbsp}} or &nbsp;) between a number and a unit symbol, ... 29 kg
(markup: 29&nbsp;kg or 29 kg)
29kg
... though with certain symbols no space is used (see "Specific units" table below) ... 23° 47′ 22″ 23 ° 47 ′ 22 ″
... a normal space is used between a number and a unit name. 29 kilograms
(markup: 29 kilograms)
To form a value and a unit name into a compound adjective use a hyphen or hyphens ...
  • a five-day holiday
  • a five-cubic-foot box
  • a 10-centimeter blade
... but a non-breaking space (never hyphen) separates a value and unit symbol.
  • a blade 10 cm long
a 10-cm blade
Plurals SI unit names are pluralized by adding the appropriate -s or -es suffix ... 1 ohm; 10 ohms
... except for these irregular forms. 1 henry; 10 henries
1 hertz; 10 hertz
1 lux; 10 lux
1 siemens; 10 siemens
10 henrys
10 hertzes
10 luxes
 
Some non-SI units have irregular plurals. 1 foot; 10 feet 10 foots
1 stratum; 10 strata (unusual) 10 stratums
Unit symbols (in any system) are identical in singular and plural.
  • grew from 1 in to 2 in
  • grew from 1 inch to 2 inches
  • grew from one to two inches
grew from 1 in to 2 ins
Powers Format exponents using <sup>, not special characters. km2
(markup: km<sup>2</sup>)
km²
(km&#178;)
Or use squared or cubed (after the unit being modified). ten metres per second squared ten metres per squared second
For areas or volumes only, square or cubic may be used (before the unit being modified). ten metres per square second
tons per square mile
sq or cu may be used with US customary or imperial units, but not with SI units. 15 sq mi
3 cu ft
15 sq km
3 cu m
Products Indicate a product of unit names with either a hyphen or a space.
  • foot-pound
  • foot pound
  • footpound
  • foot·pound
Indicate a product of unit symbols with &middot; or &nbsp;
  • ms = millisecond
  • m·s or m s = metre-second
Exception: In some topic areas such as power engineer­ing, certain products take neither space nor &middot;. Follow the practice of reliable sources in the article's topic area.
To pluralize a product of unit names, pluralize only the final unit. (Unit symbols are never pluralized.) ten foot-pounds ten feet-pounds
Ratios,
Rates,
Densities
Indicate a ratio of unit names with per. meter per second meter/second
Indicate a ratio of unit symbols with a forward slash (/), followed by either a single symbol or a parenthesized product of symbols - do not use multiple slashes. Or use −1−2, etc.
  • metre per second
  • m/s
  • m·s−1
  • mps
  • kg/(m·s)
  • kg·m−1·s−1
  • kg/m·s
  • kg/m/s
To pluralize a ratio of unit names, pluralize only the numerator unit. (Unit symbols are never pluralized.)
  • ten newton-metres per second
  • 10 N·m/s
Some of the special forms used in the imperial and US customary systems are shown here ...
  • mph = miles per hour
  • mpg = miles per gallon
  • psi = pounds per square inch
... but only the slash or negative exponent notations are used with SI (and other metric) units.
  • g/m2
  • g·m−2
gsm
  • km/h
  • km·h−1
kph
Prefixes Prefixes should not be separated by a space or hyphen. 25 kilopascals
  • 25 kilo pascals
  • 25 kilo-pascals
Prefixes are added without contraction, except as shown here: kilohm
megohm
hectare
kiloohm
megaohm
hectoare
The centi-, deci-, deca-, and hecto- prefixes should generally be avoided; exceptions include centimetre, decibel, hectolitre, hectare, and hectopascal.
  • 100 metres
  • 0.1 km
1 hectometre
Do not use M
for 103, MM for 106, or B for 109 (except as noted elsewhere on this page for M and B, e.g. for monetary values)
3 km
8 MW
125 GeV
3 Mm
8 MMW
125 BeV
Mixed
units
Mixed units are traditionally used with the imperial and US customary systems ...
  • a wall 1 ft 1 in thick
  • a wall 1 foot 1 inch thick
  • a man 6 feet 2 inches tall
  • a 6-foot 2-inch man
  • a 6 ft 2 in man
  • 1 ft, 1 in (no comma)
  • 1 foot, 1 inch
  • a man 6 foot 2 tall
  • a 6-foot 2 man
     
  • 1 US fl pt 8 oz
  • 1 US fl pt 8 US fl oz
... and in expressing time durations ...
  • 1:30:07
  • 1:30[7]
  • 1 h 30 min 7 s
  • 01h 30m 07s[8]
  • 1:30′07″
  • 1 hr 30 min 7 sec
  • 1 h 30 m 7 s
... but are not normally used in SI.
  • 1.33 m
  • 133 cm
1 m 33 cm

Quantities of bytes and bits

In quantities of bits and bytes, the prefixes kilo- (symbol k or K), mega- (M), giga- (G), tera- (T), etc., are ambiguous. They may be based on a decimal system (like the standard SI prefixes), meaning 103, 106, 109, 1012, etc., or they may be based on a binary system, meaning 210, 220, 230, 240, etc. The binary meanings are more commonly used in relation to solid-state memory (such as RAM), while the decimal meanings are more common for data transmission rates, disk storage and in theoretical calculations in modern academic textbooks.

Follow these recommendations when using these prefixes in UniWiki articles:

  • Following the SI standard, a lower-case k should be used for "kilo-" whenever it means 1000 in computing contexts, whereas a capital K should be used instead to indicate the binary prefix for 1024 according to JEDEC. (If, under the exceptions detailed further below, the article otherwise uses IEC prefixes for binary units, use Ki instead).
  • Do not assume that the binary or decimal meaning of prefixes will be obvious to everyone. Explicitly specify the meaning of k and K as well as the primary meaning of M, G, T, etc. in an article. Consistency within each article is desirable, but the need for consistency may be balanced with other considerations.
  • The definition most relevant to the article should be chosen as primary for that article, e.g. specify a binary definition in an article on RAM, decimal definition in an article on hard drives, bit rates, and a binary definition for Windows file sizes, despite files usually being stored on hard drives.
  • Where consistency is not possible, specify wherever there is a deviation from the primary definition.
  • Disambiguation should be shown in bytes or bits, with clear indication of whether in binary or decimal base. There is no preference in the way to indicate the number of bytes and bits, but the notation style should be consistent within an article. Acceptable examples include:
  •  A 64 MB (64 × 10242-byte) video card and a 100 GB (100 × 10003-byte) hard drive
  •  A 64 MB (64 × 220-byte) video card and a 100 GB (100 × 109-byte) hard drive
  •  A 64 MB (67,108,864-byte) video card and a 100 GB (100,000,000,000-byte) hard drive
  • Avoid inconsistent combinations such as A 64 MB (67,108,864-byte) video card and a 100 GB (100 × 10003-byte) hard drive. Footnotes, such as those seen in Power Macintosh 5500, may be used for disambiguation.
  • Unless explicitly stated otherwise, one byte is eight bits (see History of "byte"').

The IEC prefixes kibi- (symbol Ki), mebi- (Mi), gibi- (Gi), etc., are generally not to be used except:[9]

  • when the majority of cited sources on the article topic use IEC prefixes;
  • in a direct quote using the IEC prefixes;
  • when explicitly discussing the IEC prefixes; or
  • in articles in which both types of prefix are used with neither clearly primary, or in which converting all quantities to one or the other type would be misleading or lose necessary precision, or declaring the actual meaning of a unit on each use would be impractical.

Currencies and monetary values

Choice of currency

  • In country-specific articles, such as Economy of Australia, use the currency of the subject country.
  • In non-country-specific articles such as Wealth, use US dollars ($123), euros (€123), or pounds sterling (£123).

Currency names

  • Do not capitalize the names or denominations of currencies, currency subdivisions, coins and banknotes: not a Five-Dollar bill, four Quarters, and one Penny total six Dollars one Cent but a five-dollar bill, four quarters, and one penny total six dollars one cent. Exception: where otherwise required, as at the start of a sentence or in such forms as Interstellar Kredits.
  • To pluralize euro use the standard English plurals (ten euros and fifty cents), not the invariant plurals used for European Union legislation and banknotes (ten euro and fifty cent). For the adjectival form, use a hyphenated singular: (a two-euro pen and a ten-cent coin).

Currency symbols

  • In general, the first mention of a particular currency should use its full, unambiguous signifier (e.g. A$52), with subsequent references using just the appropriate symbol (e.g. $88), unless this would be unclear. Exceptions:
  • In an article referring to multiple currencies represented by the same symbol (e.g. the dollars of the US, Canada, Australia, New Zealand, and other countries - see [[Wikipedia:Currency symbols#dollar variants|Wikipedia:Dollar variants) use the full signifier (e.g. US$, A$) each time, except (possibly) where a particular context makes this both unnecessary and undesirable.
  • In articles entirely on EU-, UK- and/or US-related topics, all occurrences may be shortened (€26, £22 or $34), unless this would be unclear.
  • The pound sterling is represented by the £ symbol, with one horizontal bar. The double-barred symbol is ambiguous, as it has also been used for the Italian lira and other currencies. For non-British currencies that use pounds or a pound symbol (e.g. the Irish pound, IR£) use the symbol conventionally preferred for that currency.
  • If there is no common English abbreviation or symbol, follow the ISO 4217 standard. See also List of circulating currencies.

Formatting

  • A period (full stop, .) is used as the decimal point - never a comma ($6.57, not $6,57).
  • For the grouping of digits (e.g. £1,234,567) see § Grouping of digits, above.
  • Do not place a currency symbol after the accompanying numeric figures (e.g. 123$, 123£, 123€) unless that is the normal convention for that symbol when writing in English: smaller British coins include 1p, 2p, and 5p denominations. Never use forms such as $US123 or $123 (US).
  • Currency abbreviations that come before the numeric value are unspaced if they consist of a nonalphabetic symbol only, or end in a symbol (£123;   €123); but spaced
if alphabetic (R 75).
  • Ranges should be expressed giving the currency signifier just once: $250–300, not $250–$300.
  • million and billion should be spelled out on first use, and (optionally) abbreviated M or bn (both unspaced) thereafter: She received £70 million and her son £10M; the school's share was $250–300 million, and the charity's $400–450M.
  • In general, a currency symbol should be accompanied by a numeric amount e.g. not He converted his US$ to A$ but He converted his US dollars to Australian dollars or He exchanged the US$100 note for Australian dollars.
  • Exceptions may occur in tables and infoboxes where space is limited e.g. Currencies accepted for deposit: US$, SFr, GB£, . It may be appropriate to wikilink such uses, or add an explanatory note.

Conversions

  • Conversions of less-familiar currencies may be provided in terms of more familiar currencies - such as the US dollar, euro or pound sterling - using an appropriate rate (which is often not the current exchange rate). Conversions should be in parentheses after the original currency, rounding to avoid false precision (two significant digits is usually sufficient, as most exchange rates fluctuate significantly), with at least the year given as a rough point of conversion rate reference; e.g. Since 2001 the grant has been 10,000,000 Swedish kronor ($1.4M, €1.0M, or £800k, not ($1,390,570, €971,673 or £848,646).
  • For obsolete currencies, provide an equivalent (formatted as a conversion) if possible, in the modern replacement currency (e.g. decimal pounds for historical pre-decimal pounds-and-shillings), or a US-dollar equivalent where there is no modern equivalent.
  • In some cases it may be appropriate to provide a conversion accounting for inflation or deflation over time.

Common mathematical symbols

  • The Insert menu below the editing window gives a more complete list of math symbols, and allows symbols to be inserted without the HTML encoding (e.g. &divide;) shown here.
  • Spaces are placed to left and right when a symbol is used with two operands, but no space is used when there is one operand}}.
  • Use <var>...</var> for variable names: <var>base</var> + <var>ht</var> produces base + ht.
  • The {{nbsp}} template may be used to prevent awkward linebreaks.
Common mathematical symbols
Symbol name Example Markup Comments
Plus /
positive
x + y <nowiki><var>x</var> + <var>y</var></nowiki>
+y <nowiki>+<var>y</var></nowiki>
Minus /
negative
xy <var>x</var> &minus; <var>y</var> Do not use hyphen (-) or dashes (–, {{ndash}}, or ).
y &minus;<var>y</var>
Plus-minus /
minus-plus
41.5 ± 0.3 41.5 &plusmn; 0.3
−(±a) = ∓a }} &minus;(&plusmn;<var>a</var>) = &#8723;<var>a</var> }}
Multiplication,
cross
x × y <var>x</var> &times; <var>y</var> Do not use the letter x to indicate multiplication. However, an unspaced x may be used as a substitute for "by" in common terms such as 4x4.
Division, obelus x ÷ y <var>x</var> &divide; <var>y</var>
Equal / equals x = y <var>x</var> = <var>y</var>
Not equal xy <var>x</var> &ne; <var>y</var>
Approx. equal π ≈ 3.14 {{tlx|pi}} &asymp; 3.14
Less than x < y <var>x</var> &lt; <var>y</var>
Less or equal xy <var>x</var> &le; <var>y</var>
Greater than x > y <var>x</var> &gt; <var>y</var>
Greater or equal xy <var>x</var> &ge; <var>y</var>

See also

Notes and references

  1. ^ See UniWiki:Manual of Style § Commas
  2. ^ All-numeric yyyy-mm-dd dates might be assumed to follow the ISO 8601 standard, which mandates the Gregorian calendar. Also, technically all must be four-digit years, but the UniWiki is unlikely to ever need to format a far-future date beyond the year 9999.
  3. ^ These formats cannot, in general, be distinguished on sight, because there are usages in which 03-04-2007 represents March 4, and other usages in which it represents April 3. In contrast there is no common usage in which 2007-04-03 represents anything other than April 3.
  4. ^ The number in parentheses is the numerical value of the standard uncertainty referred to the corresponding last digits of the quoted result – see NIST – Use of concise notation
  5. ^ The 0x and 0 prefixes, but not 0b, are borrowed from the C programming language.
  6. ^ These definitions are consistent with all units of measure mentioned in the SI Brochure (see previous footnote) and with all units of measure catalogued in EU directive 80/181/EEC [1].
  7. ^ Only use this format if it is clear from the context whether this means hours and minutes (H:MM) or minutes and seconds (M:SS).
  8. ^ This format is used in astronomy (see the IAU Style Manual for details).
  9. ^ The UniWiki follows common practice regarding bytes and other data traditionally quantified using binary prefixes (e.g. mega- and kilo-, meaning 220 and 210 respectively) and their unit symbols (e.g. MB and KB) for RAM and decimal prefixes for most other uses. Despite the IEC's 1998 international standard creating several new binary prefixes (e.g. mebi-, kibi-) to distinguish the meaning of the decimal SI prefixes (e.g. mega- and kilo-, meaning 106 and 103 respectively) from the binary ones, and the subsequent incorporation of these IEC prefixes into the ISO/IEC 80000, consensus on Wikipedia in computing-related contexts currently favours the retention of the more familiar but ambiguous units KB, MB, GB, TB, PB, EB, etc. over use of unambiguous IEC binary prefixes.