Misplaced Pages

Revision as of 19:05, 13 August 2007

This guideline is a part of the English Misplaced Pages's Manual of Style. It is a generally accepted standard that editors should attempt to follow, though occasional exceptions may apply. Any substantive edit to this page should reflect consensus. When in doubt, discuss first on the talk page.

Shortcuts WP:DATE WP:MOSNUM MOS:DATE MOS:NUM

This part of the Manual of Style aims to achieve consistency in the use and formatting of dates and numbers in Misplaced Pages articles. Consistent standards make articles easier to read, write and edit. Where this manual provides options, consistency should be maintained within an article, unless there is a good reason to do otherwise. In direct quotations, the original text should be preserved.

In June 2005, the Arbitration Committee ruled that when either of two styles is acceptable, it is inappropriate for an editor to change an article from one style to another unless there is a substantial reason to do so. Edit warring over optional styles is unacceptable. If an article has been stable in a given style, it should not be converted without a style-independent reason. Where in doubt, defer to the style used by the first major contributor.

Non-breaking spaces

• In compound items in which numerical and non-numerical elements are separated by a space, non-breaking spaces are recommended to avoid the displacement of those elements at the end of a line.
• Non-breaking spaces are produced by keying in the html code   instead of a normal space; thus, 19 kg yields a non-breaking 19 kg.
• Non-breaking spaces are also produced by using the {{nowrap}} template; thus, {{nowrap|4:40 pm}} produces a non-breaking 4:40 pm.

Chronological items

Precise language

Avoid statements that will date quickly, except on pages that are regularly refactored, such as those that cover current events. Avoid such items as recently and soon (unless their meaning is clear in a storyline), currently (except on rare occasions when it is not redundant), in modern times, is now considered and is soon to be superseded. Instead, use either:

• more precise items (since the start of 2005; during the 1990s; is expected to be superseded by 2008); or
• an as of phrase (as of August 2007), which is a signal to readers of the time-dependence of the statement, and to later editors of the need to update the statement (see As of).

Times

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

• 12-hour clock times end with dotted or undotted lower-case a.m. or p.m., or am or pm, which are spaced (2:30 p.m. or 2:30 pm, not 2:30p.m. or 2:30pm). Noon and midnight are used rather than 12 pm and 12 am; whether midnight refers to the start or the end of a date will need to be specified unless this is clear from the context.
• 24-hour clock times have no a.m., p.m., noon or midnight suffix. Discretion may be used as to whether the hour has a leading zero (08:15 or 8:15). 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.

Dates

• Misplaced Pages does not use ordinal suffixes or articles, or put a comma between month and year.

Incorrect:	June 25th, 25th June, the 25th of June
Correct:	14 February, February 14
Incorrect:	October, 1976
Correct:	October 1976

• Date ranges are preferably given with minimal repetition (5–7 January 1979; September 21–29, 2002), using an unspaced en dash. If the autoformatting function is used, the opening and closing dates of the range must be given in full (see Autoformatting and linking) and be separated by a spaced en dash.
• Rarely, a night may be expressed in terms of the two contiguous dates using a slash (the bombing raids of the night of 30/31 May 1942); this cannot be done using the autoformatting function.
• Yearless dates (5 March, March 5) are inappropriate unless the year is obvious from the context. If there would be any doubt, include the year.
• ISO 8601 dates (1976-05-12) are uncommon in English prose, and are generally not used in Misplaced Pages. However, they may be useful in long lists and tables for conciseness and ease of comparison.

Dates of birth and death

At the start of an article on a person, his or her dates of birth and death are provided. For example: “Charles Darwin (12 February 1809 – 19 April 1882) was one of the greatest ...”

• Locations of birth and death are given subsequently rather than being entangled with the dates.
• When only the years are known: Socrates (470–399 BC) (or “BCE”) was ...”
• For a person still living: “Serena Williams (born September 26 1981) ...”, not “(September 26 1981–) ...”
• When the date of birth is unknown" “Offa (died 26 July 796) ...”
• When the date of birth is known only approximately: “Genghis Khan (c. 1162 – August 18, 1227) ...”
• When the dates of both birth and death are known only approximately: “Dionysius Exiguus (c. 470 – c. 540) ...”
• When the date of death is unknown, but the person is certainly now dead: “Robert Menli Lyon (born 1789, date of death unknown) ...”
• When only the dates of the person's reign are known, and only approximately: “Rameses III (reigned c. 1180 BCE – c. 1150 BCE) ...”
• When the person is known to have been alive (flourishing) at certain dates, “]” is used to link to floruit, in case the meaning is not familiar: “Osmund (fl. 760–72) ...”
• When the person is known to have been alive as early as about 660, and to have died in 685: “Aethelwalh (fl. c. 660–85) ...”.

Longer periods

• Months are expressed as whole words (February, not 2), except in the ISO 8601 format. Abbreviations such as Feb are used only where space is extremely limited, such as in tables and infoboxes. Do not insert of between a month and a year (April 2000, not April of 2000).

• WP:SEASON

• Seasons. Because the seasons are reversed in each hemisphere—while areas near the equator tend to have just wet and dry seasons—neutral wording is used to describe times of the year (“in early 1990”, “in the second quarter of 2003”, “around September”). Use a date or month rather than a season, unless there is a need to do so (the autumn harvest). It is ambiguous to say that Apollo 11 landed on the Moon in the summer of 1969—whose summer? Seasons are normally spelled with a lower-case initial.
• Years

• Years are normally expressed in digits; a comma is not used in four-digit years (1988, not 1,988).
• Avoid inserting the words the year before the digits (1995, not the year 1995), unless the meaning would otherwise be unclear.
• Either CE and BCE or AD and BC can be used—spaced, undotted and upper-case—to specify the Gregorian era. Be consistent within the article. AD appears before or after a year (AD 1066, 1066 AD); the other abbreviations appear after (1066 CE, 3700 BCE, 3700 BC). The absence of such an abbreviation indicates the default, CE or AD.
• When either of the two styles are acceptable it is inappropriate for a Misplaced Pages editor to change from one style to another unless there is some substantial reason for the change.
• Year ranges, like all ranges, are separated by an en dash (do not use a hyphen or slash: 2005–08, not 2005-08 or 2005/08). A closing CE/AD year is normally written with two digits (1881–86) unless it is in a different century from that of the opening year (1881–1986). The full closing year is acceptable, but abbreviating it to a single digit (1881–6) or three digits (1881–886) is not. A closing BCE or BC year is given in full (2590–2550 BCE). While one era signifier at the end of a date range still requires an unspaced en dash (12–5 BC), a spaced en dash is required when a signifier is used after the opening and closing years (5 BC – 29 AD).
• A slash may be used to indicate regular defined yearly periods that do not coincide with calendar years (the financial year 1993/94).
• Abbreviations indicating long periods of time ago—such as BP (before present), Ma and mya (million years ago), and Ga (billion years ago)—are spelled out on first occurrence.
• To indicate about, c. and ca. are preferred to circa or a question mark, and are spaced (c. 1291).

• Decades contain no apostrophe (the 1980s, not the 1980’s); the two-digit form is used only where the century is clear (the ’80s or the 80s).
• Centuries and milliennia

• There was no year 0. Thus, the first century CE was 1–100 AD, the 17th century AD was 1601–1700 CE, and the second millienium AD/CE was 1001–2000; the first century BCE was 100–1 BC; the 17th century BC was 1700–1601 BCE, and the second millennium BCE was 2000–1001 BC. Choose either the BC/AD or the BCE/CE system, but not both in the same article.
• Use numerals for centuries (the 17th century), except at the beginning of a sentence; do not capitalize century.
• The 1700s refers to a decade, not a century.

Calendars

Dates can be given in any appropriate calendar, as long as the date in either the Julian or Gregorian calendars is also given, as described below. For example, an article on the early history of Islam may give dates in both the Islamic and Julian calendars.

• Current events should be given in the Gregorian calendar.
• Dates before the adoption of the Gregorian calendar on 1582-10-15 should usually be 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 should be taken to be 1 January (see below for more details).
• Dates of events in countries using the Gregorian calendar should be given in the Gregorian calendar. This includes much of Europe from 1582, the British Empire from 1752-09-14, Russia from 1918-02-14, and so on (see the Gregorian calendar article).

Other dates are ambiguous; there are several options.

• Give the dates in the Julian calendar only. This means that the dates will match the dates in the primary sources for that period. There should be explicit indication that the dates are in the Julian calendar.
• Convert the dates to the Gregorian calendar. This means that events in different countries can be correlated. If this is not clear to the reader, this should also be indicated; and it is useful to double-check that the sources have not already done so.
• Give dates in both calendars, for example, William Shakespeare died on 1616-04-23 (Old Style)/1616-05-03 (New Style).

It is less important which option an article uses (they all convey the same facts) than that the article communicate to the reader which one it does use.

At some places and times, dates other than 1 January were used as the start of the year. The most common convention is the Annunciation Style used in Britain and its colonies, in which the year started on 25 March. See the New Year article for a list of other styles. 1 January is assumed to be the opening date for years; if there is reason to use another start-date, this should be stated in an article.

It is reasonably common, and may be useful for consistency with primary sources, to give both years for dates between January and March. For example, Elizabeth I of England died, according to her English contemporaries, on 24 March, 1602, the eve of New Year; the equivalent Gregorian date would be 3 April, 1603. Either may be used, or the common composite form 24 March, 1603; but 24 March, -3 also works. What matters, again, is to make the choice clear to the reader.

Time zones

When writing a date, first consider where the event happened and use the time zone there. For example, the date of the Attack on Pearl Harbor should be December 7, 1941 (Hawaii time/date). If it is difficult to judge where, consider what is significant. For example, if a vandal based in Japan attacked a Pentagon computer in the United States, use the time zone for the Pentagon, where the attack had its effect. If known, include the UTC date and time of the event in the article, indicating that it is UTC.

Autoformatting and linking

• Full dates, and days and months, are normally autoformatted, by inserting double square-brackets, as for linking. This instructs the WikiMedia software to format the item according to the date preferences chosen by registered users. It works only for users who are registered, and for all others will be displayed as entered.
• Do not autoformat dates that are:
  • in article and section headings,
  • on disambiguation pages,
  • within quotations (unless the original text was wikilinked).
• The autoformatting mechanism will not accept date ranges (December 13–17, 1951) or slashes (the night of 30/31 May), which must be input without using the function. Thus:
  • either ] (US editors) or ] (others) will be rendered as either January 15 or 15 January, according to a registered user's set preferences; and
  • ], ] (US editors), ] ] (others), ] (ISO), or ] will be rendered as January 15, 2001, 15 January 2001, 2001-01-15, or 2001 January 15, according to a registered user's set preferences.
• Misplaced Pages has articles on days of the year, years, decades, centuries and millennia. Link to one of these pages only if it is likely to deepen readers' understanding of a topic. Piped links to pages that are more focused on a topic are possible (]), but cannot be used in full dates, where they break the date-linking function.

Numbers

Spelling out numbers

General rule

• In the body of an article, single-digit whole numbers (from zero to nine) are spelled out; numbers of more than one digit are generally rendered as digits, but may be spelled out if they are expressed in one or two words (sixteen, eighty-four, two hundred, but 3.75, 544, 21 million).

Exceptions

• The numerical elements of dates and times are never spelled out (that is, never the seventh of January or twelve forty-five p.m.).
• Numbers that open a sentence are spelled out; alternatively, the sentence can be recast so that the number is not in first position.
• In tables and infoboxes, all numbers are expressed as numerals.
• Within a context or a list, style should be consistent (either “There were 5 cats and 32 dogs” or “There were five cats and thirty-two dogs”, not “There were five cats and 32 dogs”).
• On rare occasions when digits may cause confusion, spell out the number (thirty-six 6.4-inch rifled guns, not 36 6.4-inch rifled guns).
• Fractions are spelled out unless they occur in a percentage or with an abbreviated unit (⅛ mm, but never an eighth of a mm), or are mixed with whole numerals.
• Ordinal numbers are spelled out using the same rules as for cardinal numbers. The exception is single-digit ordinals for centuries, which may be expressed in digits (the 5th century CE). The ordinal suffix (e.g., th) is not superscripted (23rd and 496th, not 23 and 496).
• Proper names and formal numerical designations comply with common usage (Chanel No. 5, 4 Main Street, 1-Naphthylamine, Channel 6). This is the case even where it causes a numeral to open a sentence, although this is usually avoided by rewording.

Hyphenation

• Spelled-out two-word numbers from 21 to 99 are hyphenated (fifty-six), as are fractions (seven-eighths). Do not hyphenate other multi-word numbers (five hundred, not five-hundred).

Large numbers

See also Magnitude prefixes, Order of magnitude and Long and short scales.

• Commas are used to break the sequence every three places (2,900,000).
• Large rounded numbers are generally assumed to be approximations; only where the approximation could be misleading is it necessary to qualify with about or a similar term.
• Avoid overly precise values where they are unlikely to be stable or accurate, or where the precision is unnecessary in the context (“The speed of light in a vacuum is 299,792,458 metres per second” is probably appropriate, but “The distance from the Earth to the Sun is 149,014,769 kilometres” and “The population of Cape Town is 2,968,790” would usually not be, because both values are unstable at that level of precision, and readers are unlikely to care in the context.)
• Scientific notation (5.8 × 10) is preferred in scientific contexts.
• Where values in the millions occur a number of times through an article, upper-case M may be used for million, unspaced, after spelling out the first occurrence. (“She bequeathed her fortune of £100 million unequally: her eldest daughter received £70M, her husband £18M, and her three sons each just £4M each.”)
• Billion is understood as 10. After the first occurrence in an article, billion may be abbreviated to unspaced bn ($35bn).

Decimal points

• A decimal point is used between the integral and the fractional parts of a decimal; a comma is never used in this role (6.57, not 6,57).
• 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 “The response rates were 41 and 47.4 percent, respectively”).
• Numbers between minus one and plus one require a leading zero (0.02, not .02); exceptions are performance averages in sports where a leading zero is not commonly used, and commonly used terms such as .22 caliber.

Percentages

• Percent or per cent are commonly used to indicate percentages in the body of an article. The symbol '% may be more common in scientific or technical articles, or in complex listings.
• The symbol is unspaced (71%, not 71 %).
• In tables and infoboxes, the symbol is used, not the spelled-out percent or per cent.
• Ranges are preferably formatted with one rather than two percentage signifiers (22–28%, not 22%–28%).

Natural numbers

"Natural number" has two possible meanings: positive integer or non-negative integer (including zero). When referring to these numbers, explicitly use one of the these phrases rather than natural numbers, unless it clearly does not matter which is chosen.

Non-base-10 notations

For numbers expressed in bases other than base ten:

• In computer-related articles, use the C programming language prefixes 0x (zero-ex) for hexadecimal and 0 (zero) for octal. For binary, use 0b. Consider including a note at the top of the page about these prefixes.
• In all other articles, use subscript notation. For example: 137₉, 241₆, 2A9₁₂, A87D₁₆ (use _and).
• For base eleven and higher, use whatever symbols are conventional for that base. A convention is to use upper-case A–Z for digits from 10 to 35 (0x5AB3).

Units of measurement

• WP:UNITS

Which system to use

• For US-related articles, the main units are US units; for example, 10 miles (16 km).
• For UK-related, the main units are either metric or imperial (consistently within an article).
• For other country-related articles, the main units are metric; for example, 16 kilometres (10 mi).
• AmEng spells metric units with final -er (kilometer); in all other varieties of English, including CanEng, -re is used (kilometre).
• In scientific articles, SI units are the main units of measure, unless there are compelling historical or pragmatic reasons not to use them (for example, Hubble’s constant should be quoted in its most common unit of (km/s)/Mpc rather than its SI unit of s)
• If editors cannot agree on the sequence of units, put the source value first and the converted value second. If the choice of units is arbitrary, use SI units as the main unit, with converted units in parentheses.

Conversions

• Conversions to and from metric and imperial/US units are generally provided, except where inserting a conversion would make a common expression awkward (“The four-minute mile”).
• In the main text, spell out the main units and use unit symbols or abbreviations for conversions in parentheses; for example, “a pipe 100 millimetres (4 in) in diameter and 16 kilometres (10 mi) long” or “a pipe 4 inches (100 mm) in diameter and 10 miles (16 km) long”. The exception is that where there is consensus to do so, the main units may also be abbreviated in the main text after the first occurrence.
• Converted values should use a level of precision similar to that of the source value; for example, “the Moon is 380,000 kilometres (240,000 mi) from Earth”, not “(236,121 mi)”. The exception is small numbers, which may need to be converted to a greater level of precision where rounding would be a significant distortion; for example, one mile (1.6 km), not one mile (2 km).
• Category:Conversion templates can be used to convert and format many common units, including {{convert}}, which includes non-breaking spaces.
• In a direct quotation, if the text contains an obscure use of units (e.g., five million board feet of lumber), annotate it with a footnote that provides standard modern units rather than changing the text of the quotation.
• Where footnoting or citing sources for values and units, identify both the source and the original units.

Unit symbols and abbreviations

• Standard abbreviations and symbols for units are undotted. For example, m for meter and kg for kilogram (not m. or kg.), in for inch (not in., " or ″), ft for foot (not ft., ' or ′) and lb for pound (not lb. or #).
• Do not append an s for the plurals of unit symbols (kg, km, in, lb, not kgs, kms, ins, lbs).
• Temperatures are always accompanied by either °C for Celsius (35 °C), K for Kelvin (5,000 K, not 5,000 °K) or °F for Fahrenheit (62 °F); these three terms are always spelled with an upper-case initial.
• Values and unit symbols are spaced (25 kg, not 25kg). There are two exceptions: angles in degrees are unspaced (45°); and Celsius and Farenheit temperatures may be either spaced or unspaced (15°C or 15 °C).
• Squared and cubic metric-symbols are always expressed with a superscript exponent (5 km, 2 cm); squared imperial-unit abbreviations are rendered with sq, and cubic with cu (15 sq mi, 3 cu ft). A superscript exponent indicates that the unit is squared, not the unit and the quantity (3 meters squared is 9 square meters, or 9 m; 8 miles squared is 64 square miles).
• In tables and infoboxes, use unit symbols and abbreviations; do not spell them out.
• Some different units share the same name. These examples show the need to be specific.
  • Use US or imperial gallon rather than just gallon.
  • Use nautical or statute mile rather than mile in nautical and aeronautical contexts.
  • Use long ton or short ton rather than just ton (the metric unit—the tonne—is also known as the metric ton).
• Ranges are preferably formatted with one rather than two unit signifiers (5.9–6.3 kg, not 5.9 kg–6.3 kg).

Unnecessary vagueness

Use accurate measurements whenever possible.

Vague:	The wallaby is small.
Precise:	The average male wallaby is 1.6 metres (63 in) from head to tail.
Vague:	Prochlorococcus marinus is a tiny cyanobacterium.
Precise:	The cyanobacterium Prochlorococcus marinus is 0.5 to 0.8 micrometres across.
Vague:	The large herd of dugong stretched a long way down the coast.
Precise:	The dugong swam down the coast in a herd 5 kilometres (3 mi) long and 300 metres (1000 ft) wide.

Currencies

• WP:$

See also WikiProject Numismatics: Article titles

Which one to use

• In country-specific articles, such as Economy of Australia, use the currency of the country.
• In non-country-specific articles such as Wealth, use US dollars (US$123).
• If there is no common English abbreviation or symbol, use the ISO 4217 standard.

Formatting

• Fully identify a currency on its first appearance (AU$52); subsequent occurrences are normally given without the country identification (just $88), unless this would be unclear. The exception to this is in articles related to the US and the UK, in which the first occurrence may also be shortened ($34 and £22, respectively), unless this would be unclear.
• Do not place a currency symbol after the value (123$, 123£), unless the symbol is normally written thus. Do not write $US123 or $123 (US).
• Currency abbreviations that come before the number are unspaced if they end in a symbol (£123, €123), and spaced if they end in an alphabetical character (R 75). Do not place EU or a similar prefix before the € sign.
• Ranges are preferably formatted with one rather than two currency signifiers ($250–300, not $250–$300).
• Conversions of less familiar currencies may be provided in terms of more familiar currencies, such as the euro or the US dollar. Conversions should be in parentheses after the original currency, with the year given as a rough point of reference; for example, “1,000 Swiss francs (US$763 in 2005)”, rounding to the nearest whole unit.
• Consider linking the first occurrence of a symbol for less well-known currencies (₮146); it is generally unnecessary to link the symbols of well-known currencies.

Common mathematical symbols

See also Manual of Style (mathematics).

• For a negative sign or subtraction operator, use a minus sign (−), input by clicking on it in the insert box beneath the edit window or by keying in −), or an en dash (see En dashes); do not use a hyphen, unless writing code.
• For a multiplication sign, use ×, which is input by clicking on it in the edit toolbox under the edit window or by keying in × (however, the letter ex is accepted as a substitute for "by" in such terms as "4x4").
• The following signs are spaced on both sides:
  • plus, minus, plus or minus (as operators): + − ±
  • multiplication and division: × ÷
  • equals, does not equal, equals approximately: = ≠ ≈
  • is less than, is less than or equal to, is greater than, is greater than or equal to: < ≤ > ≥

The following section's wording or inclusion in this policy or guideline is disputed or under discussion. Please see the relevant talk page discussion for further information.

• Misplaced Pages style guidelines
• Misplaced Pages naming conventions