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User:Tony1/Beginners' guide to the Manual of Style

So many words.jpg

Wikipedia's Manual of Style (MoS) is a critical tool for shaping articles into a cohesive resource for our readers, and is an important driver of article improvement and the popularity of the site.

The MoS has become large and complex. This page is only about 40% of the size of the full version, but covers almost all of its points. The substantive meanings have not been intentionally altered. Inline headings have been added for every point for easy navigation. The language is trimmer, less formal and more direct. We hope the page will help editors to absorb and apply the guidelines.

This page is not authoritative; please refer to the full MoS for the definitive guidelines. Links are provided using asterisks* for access to verification and greater detail, discreetly and without clutter. Where there are several asterisks, the first usually leads to the relevant part of the MoS.

Feedback on how to improve this page is welcomed at the talk page.

Self-help writing tutorials:


General principles*

  1. Consistency. Keep style and formatting consistent within an article (unless explicitly excepted).
  2. Stability. Don't change an article from one guideline-defined style to another without a very good reason.
  3. Quotations. Generally don't apply these guidelines to directly quoted text.

Article titles and section headings**

Basic formatting

History of gene therapy, not The History of Gene Therapy.



To italicize a title, add the template {{italic title}} near the top of the article; the use of italics should conform to WP:ITALICS.

The MoS applies to all parts of an article, including the title. See especially punctuation, below. (The policy page Wikipedia:Article titles does not determine punctuation.)

  • Section headings only.
    • Hierarchy. Use the hierarchy of section headings in other articles as a model (multiple equal signs are used). Make them unique within the article; they should preferably not refer to the subject of the article or of higher-level headings.*
    • Anchors and stability notes. Described here.
    • Daughter articles. If a section is covered in greater detail in a "daughter" article, flag this by inserting {{main|Article name}} just under the section heading.*
    • Referring to a section without linking. Italicize the section name (italicize the actual section name only if it otherwise requires italics, such as the title of a book).
    • Appendix sections. Optional, but most articles have at least some. The order is (a) the subject's books and other works; (b) internal links to related Wikipedia articles; (c) notes and references; (d) recommended relevant publications not used as sources; (e) recommended websites not used as sources.*

Capital letters**

  • Generic versus title. Obama is a 21st-century American president (generic), Three prime ministers shook President Obama's hand (generic prime ministers but "President" is a title);* an exodus of refugees (generic), the Exodus (a title); South African universities, but Capetown University. Normally, prefer the over The mid-sentence, but whether the item is part of a title matters, as does common usage (the UK, but The Hague): speakers from both the UK and The Hague compared The Lord of the Rings with the Odyssey. For the use of titles and honorifics in biographical articles, see Honorific prefixes.
  • Flora and fauna. Write common (vernacular) names in lower case (oak, lion).
  • Religions. Christianity, Hinduism, the Koran, the Bible (but biblical), the Lord and his followers.*
  • Other examples. The 18th century (not Century); north; summer; capitalism versus Marxism (since the latter derives from a person's name); the Moon orbits the Earth which orbits the Sun (proper nouns in an astronomical context), but the sun rose, a planet with four moons (generic usage). If uncertain whether to capitalize, don't.
  • Redirects. Where there's an alternative capitalization for an article title, create a redirect.

Acronyms and abbreviations*

  • First occurrence. Unless very well-known (BBC), write out in full version followed by the abbreviation in parentheses; thereafter, use the abbreviated form. Don't use initial capitals in the full name just because capitals are used in the abbreviation (We used digital scanning (DS) technology, not We used Digital Scanning (DS) technology, unless it's a commercial name).
  • Plurals. Add -s or -es (DVDs; never DVD's).
  • Dots. Don't dot acronyms (with a notable exception, the optional U.S., which should not be dotted when in the vicinity of other country initialisms such as UK). Avoid USA. Abbreviations are usually not dotted, although such usages as Hon. for Honorable and Dr. for Doctor are acceptable (less so outside North American English).
  • Spacing. Don't space acronyms (N A S A, U. S.).
  • Not too many. Don't use abbreviations unnecessarily, or invent acronyms or abbreviations.


  • Emphasis. Use italics sparingly for emphasis (avoid ALL-CAPS, underlining and boldface).*
  • Titles. Use italics for the titles of works of literature and art, such as books, paintings, feature-length films, television series, and musical albums.*
  • Mentioning a word. Use italics when mentioning one word or several: The term panning is derived from panorama. For a whole sentence or more, use quotes instead.
  • Links. The opera ''[[Turandot]]'', not The opera [[''Turandot'']]; but piped text can be italicized (The [[USS Adder (SS-3)|USS ''Adder'' (SS-3)]].

Non-breaking spaces*

  • A non-breaking space (hard space) is recommended to prevent the end-of-line displacement of elements that could be awkward at the start of a new line: 17 kg can be written as 17 kg, AD 565 as AD 565, 2:50 pm as 2:50 pm, C. elegans as C. elegans, and £11 billion as £11 billion.


  • Quotation marks. Use "doubles"; make them "straight", not “curly”. We use the term (also known as "quotes") to include their use (as distinct from italics) in marking the titles of articles, chapters, songs, television episodes, short films, and other short works, and as scare quotes.
  • Final punctuation. Place it inside the quotes if part of the quoted material, and outside if not. "Don't place a final comma inside like this," unless it is in the source and relevant to the meaning. If a quote ends mid-sentence, "don't place a final dot inside like this." (This is different from the practice of many US publications and some non-US publications.)*
  • Minimal change. Preserve the original text, spelling and punctuation. Where there is a good reason not to do so, place the altered text within square brackets. If there is a significant error in the original statement, use [sic] to show that the error was not made in transcription. Normally, correct trivial spelling or typographical errors silently (harasssment to harassment).
  • Attribution. Name the author of a quote of a full sentence or more, in the main text and not in a footnote. When preceding a quotation with its attribution, take care to be neutral.
  • Sourcing. Cite sources clearly and precisely to enable readers to find the original text.*
  • Ellipses. Use them to indicate where you have omitted text from a quotation. Don't omit text that conveys essential context or in a way that alters the meaning. Ellipses are indicated by three unspaced dots. Space them on both sides, with a hard-space on the left side where necessary, except that there should be no space between an ellipsis and:
    • a quotation mark, a parenthesis or a bracket, where the ellipsis is on the inside;
    • sentence-final punctuation, or a colon, semicolon, or comma (all rare), following the ellipsis but not on the left side if they come immediately after ("... until the unification.... After the collapse ... there was chaos.". Ellipses should not normally be bracketed [...] unless the distinction between ellipsis in the original text and Wikipedia's insertion of an ellipsis needs to be made (usually with an explanation straight after the quotation). *
  • Square brackets. Use them to indicate editorial replacements and insertions within quotations. Square-bracketed wording should never alter the intended meaning of a quotation. They serve three main purposes:
    • To clarify. ("She attended [secondary] school"—where this was the intended meaning, but the type of school was unstated in the original sentence.)
    • To reduce the size of a quotation. If a source says, "X contains Y, and under certain circumstances, X may contain Z as well", it is acceptable to reduce this to "X contains Y [and sometimes Z]", without ellipsis.
    • To make the grammar work: She said that "[she] would not allow this" – where her original statement was "I would not allow this". (Generally, though, it is better to begin the quotation after the problematic word: She said that she "would not allow this".)
  • Allowable typographical changes.
    • Italics within quotations. If WP uses italics for emphasis, put an editorial note [emphasis added] at the end: "Now cracks a noble heart. Good night sweet prince: And flights of angels sing thee to thy rest" [emphasis added]. If the source uses italics for emphasis and it's desirable to stress that WP has not added the italics, write [emphasis in original] after the quote.
    • Mid-sentence case. If an entire sentence is quoted in such a way that it becomes a grammatical part of the larger sentence, the first letter loses its capitalization: It turned out to be true that "a penny saved is a penny earned".
    • Styling of dashes. Use the style chosen for the article: unspaced em-dash or spaced en-dash (see Dashes below).
    • Curly quotes (and apostrophes). Make them "straight". In quoting foreign-language text, replace foreign typographical elements such as guillemets (« ») with their English-language equivalents (i.e., with straight quotation marks).
    • Foreign spacing. Any spacing before such items as colons : remove it.
    • Faces. Generally preserve bold and italics, but don't put whole quotations in italics just because they're quotations.
    • Quotations within quotations. "Use double quotes outermost, and 'singles' within". If this results in a jostling of adjacent quote marks ("'"), consider kerning them apart slightly with CSS templates (in edit space, {{" '}}, {{' "}} and {{" ' "}}).
  • Linking. Don't link from within quotes unless there is an overriding reason to do so.
  • Block quotations. Format a long quote (more than four lines or one paragraph) as a block quotation, without enclosing it in quotation marks. Click on the edit-tool below the edit window (tab to "Wikimarkup"). Type <p> to force a paragraph space within.

Brackets and parentheses*

These rules apply to both (round brackets), often called parentheses, and [square brackets].

  • Final "external" punctuation. Like quotation marks above, the sentence punctuation comes outside the brackets (as shown here). (However, where one or more sentences are wholly inside brackets, their punctuation comes inside the brackets.)
  • Spacing. Don't put a space next to ( the inner sides ) of brackets.
  • Brackets within brackets. Use different types (for two levels, [it's usual for] square brackets [to] appear within round brackets).
  • Adjacent brackets. Avoid if possible: Nikifor Grigoriev (1885–1919) (also known as Matviy Hryhoriyiv); use commas instead, or recast the sentence.
  • Run-on lower case. A sentence that occurs within brackets in the course of another sentence doesn't generally have its first word capitalized just because it starts a sentence: Caesar demanded she ride (this was the only available transport), although consider rewording without the brackets.



  • Spacing. Periods (full-stops), commas, semicolons (; ), colons (: ), and question and exclamation marks are normally spaced to the right and not to the left. There is no guideline on whether to use one space or two after the end of a sentence, but the difference is visible only in the edit window.
  • Upper-case letters. Colons and semicolons don't normally force a capital letter in the subsequent word.
  • Serial commas. A serial comma (also called an Oxford or Harvard comma) can be inserted before a conjunction in a list (ham, chips, and eggs), but can also be omitted (ham, chips and eggs). Where including or omitting the comma avoids ambiguity, this should be done.*
  • Comma splices. They cause the reader to stumble: Oranges are an acid fruit, bananas are classified as alkaline. Correct these two independent statements to Oranges are an acid fruit; bananas are classified as alkaline, or use a comma plus a coordinating conjunction such as and or but.
  • Semicolons. The converse to a comma splice is this: Although he had been here before; I did not recognize him. Use a comma, since the second statement depends entirely on the first (through Although).
  • Colons. Use only one colon per sentence, and don't do this :- or this :– . A colon can introduce an inline list, after which use either semicolons or commas as boundaries between the items.
  • Apostrophe glyphs. Straight ( ' ), not curly ( ’ ).
  • Other signs. Use exclamation marks with restraint. Don't use clusters of question marks or exclamation marks.
  • Punctuation and inline citations. Inline citations are placed after any punctuation such as a comma or period, with no intervening space; e.g., ... are venomous.<ref>The definition of this word depends on ...</ref>, yielding ... are venomous.[1].*
  • Leakage. Restrict formatting such as bold and italics to what should properly be affected by it, and not the punctuation that is part of the surrounding sentence.*
  • Slashes. Avoid joining two words by a (forward) slash ( / ); in particular, and/or is often awkward and sometimes ambiguous. Reword if possible.**
  • Number signs. The album was Number 1 in the charts or No. 1 in the charts, not № 1 or #1.*


Hyphens (-) indicate conjunction. There are three main uses.*

  1. To distinguish between homographs (to re-dress means to dress again, but to redress means to set right).
  2. To link certain prefixes with their main word (non-Western, mid-year). NB There is a clear trend to join both elements, particularly in American English in all varieties of English (subsection, nonlinear). A hyphen is more likely when the adjacent letters are the same or are both vowels (non-negotiable, pre-industrial), or where a word is uncommon.
  3. To link related terms in compound adjectives and adverbs: (face-to-face discussion, hand-fed turkeys).
    • Disambiguation. (little-celebrated paintings isn't a reference to little paintings).
    • Before versus after the noun. Many compound adjectives are hyphenated before the noun (a light-blue handbag), but not after (the handbag was light blue), but where it might be unclear, the hyphen may be used after the noun: the turkeys were hand-fed).
    • -ly adverbs. Normally don't use a hyphen after an -ly adverb (a wholly owned subsidiary).
    • Hanging hyphens. two- and three-digit numbers.
    • Units versus symbols. Hyphenate values and units used as compound adjectives only where the unit is given as a whole word: a 9-millimetre gap, but a 9 mm gap.
    • Multi-hyphenated items. Often you can avoid multi-word hyphenated adjectives by rewording, particularly where converted units are involved (the 12-hectare-limit (29.6-acre-limit) rule might be possible as the rule imposing a limit of 12 hectares (29.6 acres)).
  • Spacing. Normally don't put a space before or after a hyphen, except when it's "hanging" (see above).
  • Double hyphens. Don't use -- as a substitute for em or en dashes.*

En dashes*

En dashes () have three distinct roles.

  1. To indicate disjunction, with several applications.
    • To convey the sense of to or through, particularly in ranges (pp. 211–19, 64–75%, the 1939–45 war, May–November) and where movement is involved (Dublin–Belfast route); but (−3 to 1, not −3–1). Spell out to when the nearby wording demands it: he served from 1939 to 1941, not he served from 1939–1941; similarly, between 1939 and 1941, not between 1939–1941.
    • To substitute for to or versus (4–3 win in the opening game, male–female ratio).
    • To substitute for and between independent elements (Canada–US border, blood–brain barrier, time–altitude graph, diode–transistor logic, Lincoln–Douglas debate; but a hyphen is used in Sino-Japanese trade, in which Sino-, being a prefix, lacks lexical independence.) If the elements operate in conjunction, rather than independently, use a hyphen.
    • To distinguish joint authors from a double-barreled (hyphenated) name: (the Smith–Hardy paper has two authors, but the Jones-Martinez paper has one.
  2. In lists, to separate distinct information within points—for example, between track titles and durations, and between musicians and their instruments, in articles about music albums. In this role, en dashes are always spaced.
  3. As a stylistic alternative to em dashes (see below).
  • Spacing. All disjunctive en dashes (Category 1, above) are unspaced, except when there is a space within either one or both of the items: the New York – Sydney flight; the New Zealand – South Africa grand final; June 3, 1888 – August 18, 1940, but June–August 1940.
  • Redirects. Article titles with dashes should have a corresponding redirect from the title with hyphens (Michelson-Morley experiment redirects to Michelson–Morley experiment). For technical reasons, en dashes are not used in image filenames.*

Em dashes*

Em dashes () indicate interruption in a sentence. They are used in two roles.

  1. Parenthetical (WP—one of the most popular web sites—has the information you need). A pair of em dashes for such interpolations is more arresting than a pair of commas, and less disruptive than parentheses (round brackets).
  2. As a sharp break in the flow of a sentence—sharper than is provided by a colon or a semicolon.

In both roles, em dashes are useful where there are already several commas; em dashes can clarify the structure, sometimes removing ambiguity. Use them sparingly—they are visually striking.

  • Spacing. Em dashes should not be spaced.
  • Regular alternative to em dashes. Spaced en dashes – such as here – can be used instead of unspaced em dashes. One style should be used consistently in an article.

Minus signs*

  • No alternatives. Don't use an en dash () or hyphen (-) for a negative sign or subtraction operator; instead, use the Unicode character for the minus sign (, keyed in as &minus;).
  • Exception. In code, a hyphen may be used.
  • Spacing. Negative signs (−8 °C) are unspaced; subtraction operators (42 − 4 = 38) are spaced.**

Chronological items*

Precise language*

Avoid statements that will age quickly (recently, soon, now) unless their meaning is fixed by the context; avoid relative terms such as currently (usually redundant), and in modern times. Instead, use either (i) more precise and absolute expressions (since the start of 2005; during the 1990s); or (ii) an as of phrase (as of August 2007).*


Context determines whether the 12- or 24-hour clock is used; in both, use colons as separators (1:38:09 pm, 13:38:09).

  • 12-hour clock. 2:30 p.m. or 2:30 pm, spaced, preferably with &nbsp;. Noon and midnight, not 12 pm and 12 am; specify whether midnight refers to the start or the end of a date unless it is clear.
  • 24-hour clock. No am, pm, noon or midnight suffixes. A leading zero is optional (08:15 or 8:15). 00:00 is midnight at the start of a date, and 24:00 at the end.


  • Day-month or month-day? The rules for choosing between these two standard formats are here.
  • Linking and autoformatting. Chronological items are not normally linked (not 1990s or 20th century), and autoformatting links for dates are now deprecated (not October 5, 2006).
  • Suffixes, articles and commas. Don't use ordinal suffixes or articles, or put a comma between month and year: 14 February, not 14th February or the 14th of February; October 1976, not October, 1976 or October of 1976.
  • Ranges. Minimize repetition, using an unspaced en dash where the range involves numerals alone (5–7 January 1979 or January 5–7, 2002) or a spaced en dash where opening and/or closing dates have internal spaces (5 January – 18 February 1979 or January 5 – February 18, 1979).
  • Slashed. the night of 30/31 May—use rarely.
  • Yearless. March 5—give the year unless it's obvious (March 5, 1956).
  • ISO dates. Generally avoid ISO 8601 format (1976-05-13) in running prose. However, it may be useful in long lists and tables for conciseness.* [Under discussion, MOSNUM]

Longer periods*

  • Months. Write as whole words (February, not 2). Use abbreviations such as Feb only where space is extremely limited, such as in tables and infoboxes.
  • Seasons as dates. The seasons are reversed in each hemisphere; use neutral wording (in early 1990, in the second quarter of 2003, not summer 1990 or Spring 2003), with obvious exceptions such as the autumn harvest and mid-spring migration.
  • Years
    • Redundancy. Not the year 1995, but 1995, unless it would be unclear.
    • Ranges. Like all ranges, separate with an en dash, not a hyphen (2005–08, not 2005-08). A closing CE/AD year is normally written with two digits (1881–86) unless in a different century (1881–1912). The full closing year is acceptable, but abbreviating it to one digit (1881–6) or three (1881–886) is not. Closing BCE/BC years are 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), use a spaced en dash when the range crosses the eras (5 BC – 29 AD).
    • Slash. A slash can indicate regular defined yearly periods that don't coincide with calendar years (the financial year 1993/94).
  • Eras
    • Which system? AD and BC are traditional, although CE and BCE are increasingly common. WP has no preference, but don't (i) mix the systems in an article, (ii) use them unless the era would be unclear, or (iii) insert conversions.
    • Formatting. Upper case, undotted and spaced (usually a hard-space): 2500&nbsp;BCE.
    • Placement. Either AD 106 or 106 AD, but the other abbreviations appear after (106 CE, 3700 BCE, 3700 BC).
    • Long ago. On first occurrence, spell out and link abbreviations such as BP (before present), ka (kiloannum), kya (thousand years ago), Ma (mega-annum), Mya (million years ago), and Ga (giga-annum or billion years ago).
    • Approximations. c. and ca. indicate around, approximately, or about. They are spaced (c.&nbsp;1291). Use a question mark instead (1291?) only if the date is questioned by the sources, rather than approximate.
  • Decades. No apostrophe (the 1980s, not 1980's); use the two-digit form (the 80s, the '80s) only where the century is clear.
  • Centuries. Use ordinal numbers, without superscripts: the 19th century, 19th-century opera (not 19th).


Numbers as figures or words*

In the body of an article, generally spell out single-digit whole numbers from zero to nine; write those greater than nine as numerals, but spelling them out is acceptable if they are expressed in one or two words (16 or sixteen, 84 or eighty-four, 200 or two hundred, but 3.75, 544, 21 million). This also applies to ordinal numbers (16th or sixteenth). Exceptions:

  • Limited space. Use numerals in tables, infoboxes, and other places where space is limited, but numbers in a table's explanatory text and comments should be consistent with the rules above.
  • Comparable quantities. 5 cats and 32 dogs or five cats and thirty‑two dogs, not five cats and 32 dogs.
  • Adjacent quantities that are not comparable. thirty-six 6.4-inch rifles, not 36 6.4-inch rifles.
  • Sentence openings. Spell out the number or recast the sentence.
  • Centuries. the 5th century CE; 12th-century manuscript.
  • Simple fractions. Normally spell them out; use the fraction form if they occur in a percentage or with an abbreviated unit (⅛ mm or an eighth of a millimeter), or if they are mixed with whole numbers. Decimal fractions are never spelled out.
  • Mathematical quantities, measurements, stock prices. Normally state them in numerals.
  • Proper names, idioms, formal numerical designations. Comply with common usage (Chanel No. 5, 4 Main Street, 1-Naphthylamine, Fourth Amendment, Seventeenth Judicial District, Seven Years' War).

Large numbers*

  • Decimal separators. Use commas to break the sequence every three places: 2,900,000.
  • Default approximation. Large rounded numbers are generally assumed to be approximations: the population is 2 million, not the population is approximately 2 million; qualify only where the approximation could be misleading. By contrast, 2,000,000 is assumed to be exact.
  • Over-precise values. Avoid 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 often 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. Preferred in scientific contexts (6.02 × 1023).
  • Abbreviation for million. Where values in the millions occur a number of times through an article, upper-case M may be used, unspaced, but spell it out on first occurrence.
  • Billion. A thousand million (109). After the first occurrence in an article, it can be abbreviated to unspaced bn ($35bn).* *

Decimal points*

  • Not a comma. 6.57, not 6,57.
  • Consistency. Make the number of decimal places consistent within a list or context (41.0 and 47.4 percent, not 41 and 47.4 percent), unless the items were measured with unequal precision (unusual).
  • Leading zero. (0.02, not .02); exceptions are performance averages in sports where a leading zero isn't commonly used, and common usage such as .22-caliber.


  • Word or symbol. Percent or per cent are commonly used to indicate percentages in running prose; % is more common in scientific or technical articles, and in listings, and should be used in tables and infoboxes.
  • Spacing. 71%, not 71 %.
  • Repetition. Normally 22–28%, not 22%–28%.
  • Change of rates. Use percentage points, not percentages, to express a change in a percentage or the difference between two percentages; for example, The agent raised the commission by five percentage points, from 10 to 15% (if the 10% commission had instead been raised by 5%, the new rate would have been 10.5%). A basis point is a hundredth of a percentage point.

Units of measurement*


  • Conversions. When different parts of the English-speaking world use different units for the same measurement, use a "primary" unit in the text followed by a conversion in parentheses: the Mississippi River is 2,320 miles (3,734 km) long; the Murray River is 2,375 kilometres (1,476 mi) long. Use the following rules to decide what the primary unit is:
  • Default primary units: SI. Generally use SI and associated units (sometimes loosely called "metric units"). However, in topics strongly associated with places, times or people, make the units most appropriate to them primary. In particular:
  • Consistency. Choose primary and converted units consistently in an article unless there is a good reason to diverge from this. (For example, UK-related articles in which SI units are primary may use imperial primary units for items where metric units have not yet been adopted in the UK.)
  • Exceptions to the need to convert:
    • Scientific articles. Conversions to customary or imperial units may be dispensed with if there is consensus to do so; in these cases, spell out or link the first occurrence of each unit.
    • Idiom. In some cases, inserting a conversion would be awkward (the four-minute mile).
  • Symbols or words? In the main text, give the primary units as words and use unit symbols or abbreviations for conversions: 100 millimetres (4 in) or 4 inches (100 mm). However, where there is consensus, abbreviate the main units too, but name them fully on their first occurrence.
  • Levels of precision. Converted values should use a level of precision similar to that of the source value, so the Moon is 380,000 kilometres (240,000 mi) from Earth, not (236,121 mi). Convert small numbers to a higher level of precision where rounding would cause a significant distortion, so one mile (1.6 km), not one mile (2 km).
  • Be precise if possible. Not Wallabies are small, but The average male wallaby is 1.6 metres (63 in) from head to tail.; not Prochlorococcus marinus is a tiny cyanobacterium., but The cyanobacterium Prochlorococcus marinus is 0.5–0.8 micrometres across.*
  • Direct quotations. Put Wikipedia's conversions for units within square brackets.
  • Clarify ambiguous units.* In a few cases, different units share the same name. Specify:
  • Spelling. American English uses -er endings for metric units: liter, kilometer; all other varieties, including Canadian, use -re: litre, kilometre.
  • Conversion templates. These templates—including {{convert}}, which inserts a non-breaking space—can be used to convert and format many common units.

Unit symbols and abbreviations*

  • No dots. Standard abbreviations and symbols for units are undotted (m, not m. for metre/meter; ft, not ft. or  for foot).
  • Plurals. Don't append an s for the plurals of unit symbols: kg, not kgs.
  • Hard spaces. Always insert (&nbsp;) between numeric values and unit symbols (25&nbsp;kg, not 25kg). Exceptions: the symbols for percent (25%) and for degrees, minutes and seconds of plane angle (5° 24′ 21.12″ N, and a 90° angle).
  • Hyphens. When values and spelled-out units form a compound adjective, hyphenate them: 10-kilometer beach, but 10 km beach.
  • Ranges. Preferably 5.9–6.3 kg, not 5.9 kg – 6.3 kg).* *
  • Temperatures. Always accompanied by °C for degrees Celsius, °F for degrees Fahrenheit, or K (never °K) for kelvin. Insert a hard-space (&nbsp;) between value and temperature symbol: 35 °C, 62 °F, and 5,000 K.
  • Degree symbol. ° (&deg;), not º or ˚.*
  • Squared and cubic units. Metric: use a superscript exponent (5 km2, 2 cm3). Imperial and US: 15 sq mi, 3 cu ft. Use <sup>2</sup> and <sup>3</sup> to produce the superscripts 2 and 3; don't use the Unicode ² and ³.
  • Limited space. In tables and infoboxes, use symbols and abbreviations, not words.
  • Familiar versus technical. Use generally familiar units unless the article is highly technical and the sources use specialized units. For specialized situations, see MOSNUM


  • Country-specific articles. Use the currency of the country; e.g., Economy of Australia.
  • Non-country-specific articles. Use US dollars; e.g., Economics.
  • Full or short form? Use the full name on its first appearance (52 Australian dollars), and thereafter the symbol (just $88), or the full abbreviation (AU$) if necessary to distinguish from other currencies that use the same symbol. The exception to this is in articles related entirely to US-, UK- or Eurozone-related topics, in which the first occurrence may be shortened ($34, £22 and €26) if clear.
  • Shortage of space. Use the short forms in tables, infoboxes and parenthetical notes.
  • Order of elements Don't invert (123$, 123£, 123€), unless a symbol is normally written as such. Don't write $US123 or $123 (US).
  • Spacing. Currency abbreviations that come before the number are unspaced if they consist of or end in a symbol (£123), and spaced if alphabetic (R 75).
  • Default to ISO. If there is no common English abbreviation or symbol, use the ISO 4217 standard.
  • Ranges. Preferably format with one rather than two currency signifiers ($250–300, not $250–$300).
  • Conversions. Less familiar currencies may be converted to more familiar currencies in parentheses after the original currency, rounding to avoid false precision and noting the conversion as approximate, with at least the year given; e.g., Since 2001 the grant has been 10,000,000 Swedish kronor (about US$1.4M as of August 2009).
  • Obsolete currencies. If possible, provide a conversion in the modern replacement currency (e.g., decimal pounds for historical pre-decimal pounds-and-shillings figures), or at least a US-dollar equivalent where there is no modern equivalent.
  • Linking. If possible, link the first occurrence of lesser-known currencies (146 Mongolian tögrögs).
  • Lower case. Don't force capital letters on the names of currencies, currency subdivisions, coins and banknotes.
  • Pound sterling. The symbol is £, with one horizontal bar. For non-British currencies that use a pound symbol, use the conventional symbol for that currency.

Common mathematical symbols**

  • Minus sign. For a negative sign or subtraction operator, use a minus sign () by clicking on the edit tool under the edit window or by typing &minus; (don't use a hyphen (-) unless writing code).
  • Multiplication sign. Between numbers, use ×, input by clicking on it in the edit toolbox under the edit window, or by typing &times;. Don't use an asterisk (*) unless writing code). Don't use the letter "ex" (x, although this is acceptable as a substitute for by in such terms as 4x4.
  • Spacing. Symbols for binary operators and relations are spaced on both sides: + ± × ÷ = < >
  • Exponential notation. an (typed as a<sup>n</sup>), not a^n. Don't use E notation.



  • Nouns
  • For most singular nouns, add 's (my daughter's achievement, Cortez's, the boss's, Illinois's, Descartes's, Verreaux's). Exceptions: (for goodness' sake, for his conscience' sake).
  • For singular nouns ending with just one s (sounded as /s/ or /z/), there are three practices:
    1. Add 's (James's house).
    2. Add just ' (James' house).
    3. Add either ' or 's according to the pronunciation:
      • Add just ' if the possessive isn't pronounced as another syllable (Sam Hodges' son);
      • Add 's if it is (Morris's works);
      • If there is disagreement over the pronunciation, negotiate the choice.
      • Possessives of certain classical and biblical names may have traditional pronunciations which may be deemed as taking precedence: Jesus' answer and Xerxes' expeditions, but Zeus's anger;
  • Consistency. Whichever option is chosen, apply it consistently in an article.
  • Common plural nouns. Where the final s is pronounced, add just ' (both my dogs' collars); where there is not a final, pronounced s, add 's (women's priorities), but where rewording is an option, this may be better.
  • For inanimate objects, rewording may be an option (the location of Vilnius).
  • Official names. Don't alter, even for consistency (St Thomas' Hospital, never St Thomas's Hospital).
  • Its. The singular neutral possessive (the dog chased its tail) has no apostrophe.

Collective plurals***

Some words can refer to either a single entity or the members that compose it (army, company, crowd, fleet, government, majority, number). In British English, such words are commonly treated as singular or plural according to context. Names of towns and countries take plural verbs when they refer to sports teams but singular verbs when they refer to the actual place (or to the club as a business enterprise): in England played Germany, the word England refers to a football team. In North American English, these words are almost always treated as singular. The United States is normally treated as singular.

Other issues

  • I and we. Never use them (quotations excepted), except that we in historical articles can be used to mean the modern world as a whole (The text of De re publica has come down to us with substantial sections missing).
  • You. Outside quotations, generally avoid it: Visitors to the valley reported that the effects of the war were clear, not When you moved through the valley, the effects of the war were clear.
  • Contractions. Do not use contractions: do not instead of don't, cannot instead of can't, is not instead of isn't (quotations excepted).
  • Instructional and presumptuous language. Don't instruct the readers (remember that and note that). Don't presume readers' knowledge (of course, naturally, obviously, clearly, actually).*
  • Subset terms. These identify a set of members of a larger class (including, such as, e.g.,, for example). Don't use two at once (Among the most well-known members of the fraternity include ...; The elements in stars include hydrogen, helium and iron, etc.). Don't use including to introduce a complete list, where comprising, consisting of or composed of would be correct.
  • Ambiguous or. Wild dogs, or dingoes, inhabit this stretch of land. Are wild dogs and dingoes the same or different? For one case, wild dogs (dingoes) inhabit (meaning dingoes are wild dogs); for the other case, either wild dogs or dingoes.*
  • Contested vocabulary. Avoid items that are either not widely accepted or of strained formality; e.g., thusly, overly, whilst, amongst, and as per.***
  • Ampersands. Avoid the ampersand (&) in favor of and. Exceptions: retain & in titles of works or organizations, and use with consistency and discretion in tables, infoboxes, and other contexts where space is limited.*

National varieties of English**

The English Wikipedia does not prefer any major national variety of the language, and editors should recognize the differences between them as superficial. Cultural clashes over spelling and grammar are avoided by using the following four guidelines.

Strong national ties to a topic

Existing variety

Where there are no strong national ties to the topic and an article has evolved using predominantly one variety, it should conform to that variety. In the early stages of writing an article, the variety preferred by the first major contributor to the article should be used. Where an article that is not a stub shows no signs of which variety it is written in, the first person to make an edit that disambiguates the variety is equivalent to "the first major contributor".


Each article should consistently use the same conventions of spelling, grammar and punctuation. There are three exceptions:

  • Quotations. Retain the original variety, although the precise styling of punctuation marks such as dashes, ellipses, apostrophes, and quotation marks should be made consistent with the surrounding article.
  • Proper names. Use the original spelling (United States Department of Defense, Australian Defence Force).
  • Meta-comparisons. Explicit comparisons of varieties of English.

Opportunities for commonality

  • Common across the language. Try to find words that are common to all varieties of English, especially in article names: fixed-wing aircraft is preferred to the national varieties aeroplane (BrEng) and airplane (AmEng). Avoid ambiguity (alternative or other route, not alternate, which may mean alternating in some varieties.
  • Redirects. If one variant spelling appears in an article name, redirect pages are made to accommodate the other variants, as with Artefact and Artifact, so that all variants can be used in searches and in linking.
  • Gloss uncommon items. Terms that are uncommon in some varieties of English, or that have divergent meanings, may be explained to prevent confusion.
  • Other resources. Articles such as English plural and American and British English differences provide information on the differences between the major varieties.

Gender-neutral language**

Use gender-neutral language where this can be done with clarity and precision. This does not apply to direct quotations or the titles of works (The ascent of man), or where all referents are of one gender, such as in an all-female school (when any student breaks that rule, she loses privileges).

Foreign terms****

Use foreign words and phrases sparingly.

  • Where not commonly used in English. Use italics.
  • Where commonly used in English. Italics are not required for loanwords and borrowed phrases such as Gestapo, samurai, vice versa and esprit de corps. Rule of thumb: follow the major English-language dictionaries.
  • Proper names. Not usually italicized, including place names.
  • Romanization. Names not originally in a Latin alphabet—such as those adapted from Greek, Chinese, and Cyrillic scripts—must be romanized into characters generally intelligible to English-speakers. Don't use a systematically transliterated name if there's a common English form (Tchaikovsky, Chiang Kai-shek).
  • Spelling. Normally spell a foreign name consistently in the title and throughout the article. Adopt the spelling most commonly used in English-language references for the article, unless those spellings are idiosyncratic or obsolete.**
  • Diacritics.* Usage is neither encouraged nor discouraged, and depends on whether they appear in verifiable reliable sources in English and on specialized Wikipedia guidelines. Place redirects at alternative titles, such as those without diacritics.


  • Subject's preference. Normally use the term the person uses for themself, and for a group, the terms it most commonly uses for itself. (For example, the article Jew demonstrates that most Jews prefer that term to "Jewish person".)
  • Address disputes by reference to Verifiability, NPOV, and Naming conventions.
  • Gender. Refer to any person whose gender might be at issue by using the gendered nouns, pronouns, and possessive adjectives that reflect that person's most recent expressed gender self-identification. This applies in a context referring to any phase of that person's life. Nevertheless, avoid confusing or seemingly logically impossible text (She fathered her first child).
  • Avoid unnecessary vagueness. Ethiopian, for example, not African, especially where there may be a risk of stereotyping.
  • Certain adjectives as nouns. Black people, not blacks, gay people, not gays, people with disability, not the disabled, and other such usage that may be sensitive.
  • Arab. This refers to people and things of ethnic Arab origin, who don't necessarily speak Arabic. Never to be confused with Muslim or Islamic.
  • Exception. Direct quotations.



  • Lead. Start with a right-aligned lead image or infobox.*
  • Placement. Multiple images in the same article can be staggered right-and-left (for example: Timpani). Images should be laid out so they work well with browser windows as narrow as 800 pixels and as wide as 2000 pixels. See this tutorial for how to group images and avoid "stack-ups". Place images inside the section they belong to (after the heading and any links to other articles), and not straying above the heading.
  • Direction of face. It's usually preferable to place images of faces so the face or eyes look toward the text.
  • Alteration. An image should be reversed or substantially altered only if this clearly assists the reader (for example, cropping a work of art to focus on a detail discussed in the text). Note any such alteration in the caption. Don't reverse an image just for the sake of layout preferences.
  • Text as image. Avoid entering textual information as an image solely for graphic utility. Such text should also appear in the image's alt text, caption, or other nearby text.
  • Commons links. Use {{Commons}} to link to more images on Commons, wherever possible.
  • Galleries. The use of galleries should be in keeping with Wikipedia's image use policy.


Most pictures should be displayed so they are between 100 and 400 pixels wide. The maximum should generally not exceed 500 pixels in height or 400 pixels in width, so the image can be comfortably displayed within the text on the smallest displays in common use.

  • Thumbnails. The thumbnail option ([[(The file name)|thumb|(Your caption)]]) results in a default width of 180 pixels, although logged-in users can set a different default in their user preferences. [Thumbnail size currently under review.]
  • Why resize? An image may benefit from a size other than the default. Typical reasons for resizing include the following:
    • A small region is the focus of interest, but cropping to that region would reduce the coherence of the image (enlarge).
    • There are important details, including maps, diagrams, and charts containing important text that would be unreadable at the default size (enlarge).
    • Detail is relatively unimportant, such as some national flags (make smaller).
    • The aspect ratios are extreme or otherwise distort or obscure the image (make smaller).
    • It is the lead image, which should usually be no wider than 300px.
  • How to resize. Either:
    • specify pixel width (e.g., [[(The file name]|thumb|240px|(Your caption)]]); or
    • use the upright option ([[(The file name)|upright=1.67|(Your caption)]]) or the frameless option ([[(The file name)|frameless|upright=1.67|(Your caption)]]). A setting of 1.67 resizes a plain picture to about 300 pixels in width (the 180-pixel default × 1.67).
  • Centering. The width can be even wider if the image is centered ([[(The file name)|center|450px|(Your caption)]]).
  • Templates. {{Wide image}} and {{Tall image}} display images that would otherwise be too wide or tall.


  • Role. Use captions to explain the relevance of an image to the article. Photographs and other graphics should always have captions unless they are "self-captioning" (such as reproductions of album or book covers) or when they are unambiguous depictions of the subject of the article.
  • Complete sentence or fragment. Most captions are not complete sentences, but merely nominal groups (sentence fragments) that should not end with a period. If a complete sentence occurs in a caption, end that sentence, and any sentence fragments, with a period. Regardless, normally start captions with a capital letter.
  • Succinctness. Make captions succinct; more information about the image can be included on its description page, or in the main text.
  • Italics. Don't italicize a caption just because it's a caption.

Alt text*

Alternative text describes the image for readers who cannot see the image, such as visually impaired readers or those using web-browsers that do not download images. By contrast, captions are intended to explain or supplement an image that is visible. Images need not have alt text; editors should ask themselves how much sighted readers would lose if the picture were blanked, and how easily it can be described verbally. Alt text should not merely repeat the caption or the main text of the article. Instructions on adding alt text to equations and images is here. The Altviewer tool displays an article's alt text.

Bulleted and numbered lists***

Don't use a list if a passage reads easily in running prose.

  • Blank lines between items. Avoid.
  • Numbers. Use them rather than bullets only if:
    • you need to refer to the elements by number;
    • the sequence of the items is critical; or
    • the numbering has independent meaning, e.g., in a listing of musical tracks.
  • Consistent grammar. Use the same grammatical form for all elements in a list; don't mix the use of sentences and sentence fragments as elements.
    • When the elements are complete sentences, format them using sentence case with a final period.
    • When the elements are sentence fragments, they are typically introduced by a lead fragment ending with a colon. When these elements are titles of works, they retain the original capitalization of the title; other elements are formatted consistently in either sentence case or lower case. End each element with a semicolon, and with a period instead for the last element. Alternatively (especially when the elements are short), no final punctuation is used at all.



  • Make links only where they are relevant to the context. It is not useful and can be very distracting to mark all possible words as hyperlinks. Links should add to the user's experience; they should not detract from it by making the article harder to read. A high density of links can draw attention away from the high-value links that you would like your readers to follow up. Redundant links clutter the page and make future maintenance harder. However, ensure that the high-value links are provided.
  • Adjacent links. Avoid where possible (often one will "chain-link" to the other, anyway).
  • Be specific where possible. Link to a target page section using the pound (hash) sign where it is more focused ([[Guitar#Types]], usually piped for ease of reading thus: [[Guitar#Types|Types of guitar]]).
  • Piped links. Linking can be either direct ([[History of Johannesburg]]) or piped for the linguistic context ([[History of Johannesburg|Johannesburg's rich history]], displayed as Johannesburg's rich history).
  • Check the target. Ensure the destination is the intended article and not a disambiguation page.
  • Initial capitalization. The first letter should be capitalized only where this is normally called for, or when specifically referring to the linked article by name: Cane toads are poisonous, but lizards are typically not (see Venom).

External links**

  • Placement. Articles can include an external links section at the end to list links to websites outside Wikipedia that contain further information, as distinct from citing sources. External links are not normally used in the body of an article.
  • Rationing. Avoid listing an excessive number of external links; Wikipedia is not a link repository.
  • Formatting. The standard format is a primary heading == External links == followed by a bulleted list of links. External links should identify the link and briefly indicate its relevance to the article subject. For example:

*[ History of NIH]
*[ National Institutes of Health homepage]

The first gap triggers the boundary between link and pipe, so these will appear as:


Formatting issues

  • Generally avoid specifying. Formatting issues such as font size, blank space and color are issues for the Wikipedia site-wide style sheet and usually should not be specified. If you absolutely must specify a font size, use a relative size (font-size: 80%), not an absolute size (font-size: 8pt).
  • Custom font styles. Use judiciously, since they reduce:
    • consistency—the text will no longer look uniform;
    • usability—people with custom stylesheets (for accessibility reasons, for example) may have difficulty in overriding them, and they might clash with a different skin.*
  • Color coding. Generally don't use it alone to convey information. Many colors are not accessible to people with color blindness or on black-and-white printouts. Avoid using shades of red and green in the same display. Viewing with Vischeck can help to improve the use of colors in this respect.**
  • Keep markup simple. Use the simplest markup to display information in a useful and comprehensible way. Markup may appear differently in different browsers. Use HTML and CSS markup sparingly and only with good reason. Minimizing markup in entries allows easier editing. Don't use the CSS float or line-height properties, because they break rendering on some browsers when large fonts are used.*
  • Scrolling lists. Scrolling lists and boxes that toggle text-display between hide and show are acceptable in infoboxes and navigation boxes, but should never be used in article prose or references because of issues with readability, accessibility, and printing.*
  • Invisible comments. Editors use them to communicate with each other within article text in edit mode. They are useful for flagging an issue or leaving instructions about part of the text, where this is more convenient than raising the matter on the talk page. Don't use them so much that they clutter, and check that they don't change the formatting, such as by introducing unintended white space in display mode. To enter an invisible comment, enclose it within <!-- and -->; e.g., <!--If you change this section title, please also change the links to it on the pages ...-->.*
  • Tables. How to construct them is explained here and here.


Use the IPA. For ease of understanding across varieties of English, fairly broad IPA transcriptions are usually provided for English pronunciations.***