Utilisateur:Busiris/Wikipédia:Manuel de style

Ce manuel de style est un guide qui poursuit l'objectif de rendre l'espace encyclopédique facile à lire. Une façon de présenter l'information vaut souvent une autre, mais une harmonie de style est utile pour permettre à l'encyclopédie d'être plus facilement lue ou écrite. Le projet aura une plus grande cohérence si ces recommandations sont suivies.

Le manuel de style ne prétend pas avoir le dernier mot sur le style de Wikipédia : tout ce qui est ici devrait être appliqué avec discernement, et non de façon automatique. Il ne fixe pas de lois rigides, mais des principes sur lesquels les contributeurs se sont mis d'accord dans la plupart des circonstances. Ainsi, vous êtes encouragés à suivre ces recommandations, avec une certaine flexibilité. Si une règle vous empêche d'écrire une encyclopédie pédagogique et utile, ignorez-la.

Quel style utiliser ?

Si cette page ne détermine pas quel usage est souhaité, ou ne tranche pas la difficulté :

• utilisez d'autres ressources fiables, comme les guides de styles listés plus bas.
• faites connaitre vos problèmes, ou demandez des avis sur Discussion Wikipédia:Manuel de style, ou des contributeurs expérimentés pourront faire partager leurs conseils.
• vous pouvez aussi regarder dans les historiques de certains articles fréquentés pour voir comment les contributeurs ont écarté les difficultés.

[Guides de style qui font autorité en langue française ?]

Article titles

If possible, the article’s topic is the subject of the first sentence of the article, for example, “This Manual of Style is a style guide” instead of “This style guide is known as …”. If the article title is an important term, it appears as early as possible. The first (and only the first) appearance of the title is in boldface, including its abbreviation in parentheses, if given. Equivalent names may follow, and may or may not be in boldface. Highlighted items are not linked, and boldface is not used subsequently in the first paragraph.

This example illustrates the use of boldface in the Vienna article:

Vienna (allemand : Wien [viːn], see also its other names) is the capital of Austria and one of that country’s nine states.

The normal rules for italics are followed in choosing whether to put part or all of the title in italics:

Tattoo You is an album by The Rolling Stones, released in 1981.

If the topic of an article has no name, and the title is simply descriptive—like Effects of Hurricane Isabel in Delaware or Electrical characteristics of a dynamic loudspeaker—the title does not need to appear verbatim in the main text; if it does, it is not in boldface:

A dynamic loudspeaker driver’s chief electrical characteristics can be shown as a curve, representing the …

How to edit a page gives advice on making items bold, italic, or both.

Sections and headings

Markup

Unspaced multiple equal signs are the style markup for headings (also called section titles). The triple apostrophes ( ''' ) that make words appear in boldface are not used in headings.

The heading for the section you are now reading was created with double equal signs:

==Sections and headings==

The heading for the current subsection was created with triple equal signs:

===Markup===

Wording

In headings and subheadings:

• only the first letter of the first word, and the first letter of proper nouns are capitalized; all other letters are in lowercase (for example, “Rules and regulations”, not “Rules and Regulations”);
• special characters—such as the slash (/), plus sign (+), curly braces ({}) and square braces ([])—are avoided, and the word “and” is spelled out in place of an ampersand (&), unless the ampersand is part of a formal name;
• links are avoided in favor of linking the first occurrence of the item in the section text;
• the wording tends to be short (more than 10 words may defeat the purpose);
• articles (a, an, and the) are typically avoided, and never occur first;
• pronouns and repetitions of the article title are avoided;
• the wording is not identical to that in any other heading or subheading in the article.

Section management

• Headings and subheadings provide an overview in the table of contents and allow readers to navigate through the text more easily. Subheadings are particularly appropriate for breaking up longer sections.
• Headings and subheadings are changed only after careful consideration, because this will break any section links to them from the same and other articles.
• If you link to a section, leave an editor’s note to remind others that the title is linked. List the names of the linking articles, so that if the title is altered, others can fix the links more easily. For example: ==Evolutionary implications==<!-- This section is linked from [[Richard Dawkins]] and [[Daniel Dennett]] --> .
• If you refer to a section without linking, italicize the section name; for example, you are now reading the section on Section management.
• If you link to a section, italicize the section name only if it otherwise requires italics (for example, if it is the title of a book). Linking a term provides sufficient indication that you are using a term as a term, which is what you would otherwise use italics for.
• If you change a section title, try to locate and fix broken links; for example, googling wikipedia “section management” will probably yield links to the current section.

Capital letters

There are differences between the major varieties of English in the use of capitals (uppercase letters). Where this is an issue, the rules of the cultural and linguistic context apply, as for spelling. Consistency is maintained within an article.

Capitals are not used for emphasis. Where wording cannot provide the emphasis, italics are used.

• Modèle:Not correct Against common belief, aardvarks are Not the same as anteaters.
• Modèle:Not correct Against common belief, aardvarks are NOT the same as anteaters.
• Modèle:Correct Against common belief, aardvarks are not the same as anteaters.

Titles

• When used as titles (that is, followed by a name), items such as president, king and emperor start with a capital letter: President Nixon, not president Nixon. The formal name of an office is treated as a proper noun: “Hirohito was Emperor of Japan” and “Louis XVI was King of France” (where King of France is a title). Royal titles are capitalized: Her Majesty and His Highness; exceptions may apply for particular offices.
• When used generically, such items are in lower case: “De Gaulle was the French president” and “Louis XVI was the French king”. Similarly, “Three prime ministers attended the conference”, but “The British Prime Minister is Gordon Brown”. (A rule of thumb is this: when the modifier is the specific article the, we use Prime Minister; when the non-specific a applies, we use prime minister).
• For the use of titles and honorifics in biographical articles, see Honorific prefixes.

Religions, deities, philosophies, doctrines, and their adherents

• Religions and their followers, and the related adjectives, start with a capital letter. The Latter Day Saint movement has particular capitalization and naming conventions.
• Deities start with a capital letter: God, Allah, Freya, the Lord, the Supreme Being and the Messiah (articles such as the are not capitalized). The same is true when referring to major religious figures, such as Muhammad, by terms such as the Prophet. Transcendent ideas in the Platonic sense start with a capital letter, as in Good and Truth. Pronouns referring to deities, or nouns (other than names) referring to a material or abstract representation of a deity, human or otherwise, do not begin with a capital letter. Thus, while it is correct to say “He prayed to Wotan”, since Wotan in this case is a proper name, “He prayed to the God Wotan” should be “He prayed to the god Wotan”. Thus, the following sentence is correct: “It was thought that he prayed to God, but it turned out that he prayed to one of the Norse gods.”
• Mythical creatures such as elves, fairies, nymphs and genies do not start with a capital letter. There are exceptions in some works of fantasy, such as those of JRR Tolkein, where initial capitals are used to indicate that the mythical creatures are regarded as ethnicities or races.
• Philosophies, theories and doctrines do not begin with a capital letter, unless the name derives from a proper noun: lowercase republican refers to a system of political thought; uppercase Republican refers to a specific Republican Party (because each party name is a proper noun).

Calendar items

• Months, days and holidays start with a capital letter: June, Monday, the Fourth of July (when referring to the U.S. Independence Day, otherwise July 4 or 4 July).
• Seasons, in almost all instances, are lowercase: “this summer was very hot”; “the winter solstice occurs about December 22”; “I’ve got spring fever”. When personified, season names may function as proper nouns, where they should be capitalized: “I think Spring is showing her colors”; “Old Man Winter”.
• Dates are normally followed by a comma: “In 2001, Bob got married”; “On April 10, I will be having a party”, but not when they are used to modify other terms: “The 1993 edition has several errors”.

Animals, plants, and other organisms

• Scientific names for genera and species are italicized, with a capital initial letter for the genus but no capital for the species. For example, the tulip tree is Liriodendron tulipifera, and humans are Homo sapiens. Taxonomic groups higher than genus are generally roman, with an initial capital; for example, gulls are in the family Laridae, and we are in the family Hominidae.
• Common (vernacular) names have been a hotly debated topic, and it is unresolved whether the common names of species start with a capital. As a matter of truce, both styles are acceptable (except for proper names). Where used in an article title, a redirect from the alternative form is created.

Celestial bodies

• Sun, earth, and moon are proper nouns in an astronomical context, but not elsewhere: thus, “The Sun is a main sequence star, with a spectral class of G2”; but “The sun was peeking over the mountain top”. These terms are proper nouns only when they refer to specific celestial bodies (our Sun, Earth and Moon): so “The Moon orbits the Earth”, but “Pluto’s moon Charon”.
• Other planets and stars are proper nouns and start with a capital letter: “The planet Mars can be seen tonight in the constellation Gemini, near the star Pollux.” Where a name has multiple words, it is treated like other proper nouns where each leading letter is capitalized: “Alpha Centauri” and not “Alpha centauri”.

Directions and regions

• Directions such as north are not proper nouns and are therefore lowercase. The same is true for their related forms: someone might call a road that leads north a northern road, compared with the Great North Road. Composite directions may or may not be hyphenated (northeast and north-east, Southeast Asia and South-east Asia).
• Regions that are proper nouns, including widely known expressions such as Southern California, start with a capital letter. Follow the same convention for related forms: a person from the Southern United States is a Southerner. Regions of uncertain proper-noun status are assumed not to have attained it.

Institutions

• Proper names of institutions (for example, the University of Sydney, New York-Presbyterian Hospital, George Brown College) are proper nouns and require capitalization. Where a title starts with the, it typically starts with lowercase t when the title occurs in the middle of a sentence (“a degree from the University of Sydney”); usage on the webpage of the institution may confirm whether this is the case.
• Generic words for institutions (university, college, hospital, high school) require no capitalization:
• Modèle:Not correct (generic): The University offers programs in arts and sciences.
• Modèle:Correct (generic): The university offers …
• Modèle:Correct (title): The University of Ottawa offers …

Acronyms and abbreviations

Initial spelling out

Readers are not necessarily familiar with particular acronyms, such as NASA (pronounced as a word) or initialisms, such as PBS (pronounced by spelling it out). The standard practice is to spell out the item on its first occurrence, followed by the abbreviation in parentheses. For example, “The New Democratic Party (NDP) won the 1990 Ontario election with a significant majority. However, the NDP quickly became unpopular with the voters.” Initial capitals are not used in a spelled out item just because capitals are used in the abbreviation.

• Modèle:Not correct The new Digital Light Processing (DLP) technology
• Modèle:Correct The new digital light processing (DLP) technology
• Modèle:Correct (title): produced by the British Broadcasting Corporation (BBC)

Within parentheses

If a term is already in parentheses, use a comma and or to indicate the acronym; for example, “They first debated the issue in 1992 (at a convention of the New Democratic Party, or NDP).”

Plural forms

Acronyms and initialisms are pluralized by adding -s or -es. For example, “They produced three CD-ROMs in the first year”.

Periods and spaces

Many periods and spaces that were traditionally required have now dropped out of usage. For example, PhD is preferred to Ph.D. and Ph. D.. Periods are retained in abbreviations that cannot otherwise be clearly identified.

HTML elements

The software that Wikipedia runs on does not support HTML abbreviation elements (<acronym> or <abbr>), so these tags are not to be inserted into the source. (See Mediazilla:671.)

Italics

Emphasis

Italics are used sparingly to emphasize words in sentences (bolding is normally not used at all for this purpose). Generally, the more highlighting in an article, the less the effect of each instance.

Titles

Italics are used for the titles of works of literature and art. The titles of articles, chapters and other short works are not italicized but are enclosed in double quotation marks.

Words as words

Italics are used when citing a word or letter (see use-mention distinction). For example, “The term panning is derived from panorama, a word coined in 1787.” “The most commonly used letter in English is e.”

Quotations in italics

An entire quotation is not italicized solely because it is a quotation.

Italics within quotations

Italics are used within quotations if they are in the source material, or to add emphasis; if the latter, an editorial note “[emphasis added]” appears at the end of the quotation. For example: “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 is desirable to stress that Wikipedia has not added the italics, the editorial note “[emphasis in original]” appears after the quote.

Effect on nearby punctuation

Italicization is restricted to what should properly be affected by italics, and not the surrounding punctuation.

Modèle:Not correct What are we to make of that?

Modèle:Correct What are we to make of that? [The question mark applies to the whole sentence, not just to that.]

Modèle:Correct Four of Patrick White’s most famous novels are A fringe of leaves, The aunt’s story, Voss and The tree of man. [The commas and and are not italicized.]

Italicized links

The italic markup is outside the link markup, or the link will not work.

Modèle:Not correct The opera [[''Turandot'']] is his best.

Modèle:Correct The opera ''[[Turandot]]'' is his best.

Foreign terms

Modèle:Seealso Foreign words are used sparingly.

No common usage in English

Wikipedia prefers italics for phrases in other languages and for isolated foreign words that do not yet have common usage in English.

Common usage in English

Loan words and phrases that have common usage in English—praetor, Gestapo, samurai, esprit de corps—do not require italicization. A rule of thumb is: do not italicize words that appear in an English language dictionary.

Spelling and transliteration

For terms in common usage, anglicized spellings are used, or native spellings if they use the Latin alphabet; diacritics are optional. Where native spellings in non-Latin scripts (such as Greek and Cyrillic) are given, they appear in parentheses, and are not italicized, even where this is technically feasible.

Quotations

Minimal change

Wherever it is reasonable to do so, the style that was used in the original text is preserved. Where there is a good reason not to preserve the original style, the changes are supported by the insertion of an editorial explanation, usually within in square brackets.

Attribution

The author of a quote of a full sentence or more is named; this is done in the main text and not in a footnote. An exception is that attribution is unnecessary for well-known quotations (e.g., from Shakespeare) and those from the subject of the article or section.

Quotations within quotations

An exception to the previous rule is when a quotation encloses a quotation: here, Wikipedia’s style is used, starting with double-quotes outermost and working inward, alternate single-quotes with double-quotes. For example, the following quotation: “She disputed his statement that ‘Voltaire never said “I disapprove of what you say, but I will defend to the death your right to say it” ’ ”. Adjacent quote marks, as at the end of this example, are separated by a non-breaking space (&nbsp;).

Linking

Unless there is a good reason to do so, Wikipedia avoids linking from within quotes, which may clutter the quotation, violate the principle of leaving quotations unchanged, and mislead or confuse the reader.

Block quotations

A long quote (more than four lines) is formatted as a block quotation, which Wikimedia’s software will indent from both margins. Block quotes are not enclosed in quotation marks.

Punctuation

Quotation marks

Double or single

We use “double quotes”, and ‘single quotes’ for quotations within quotations.

Inside or outside

Punctuation marks are placed inside the quote marks only if the sense of the punctuation is part of the quotation (this system is referred to as logical quotations).

• Modèle:Correct Arthur said that the situation is “deplorable”. (When a sentence fragment is quoted, the period [full stop] is outside.)
• Modèle:Correct Arthur said, “The situation is deplorable.” (The period is part of the quoted text.)
• Modèle:Not correct Martha asked, “Are you coming?” (When quoting a question, the question mark is inside because the quoted text itself was a question.)
• Modèle:Correct Did Martha say, “Come with me”? (The very quote is being questioned, so here, the question mark is correctly outside; the period is omitted.)

Article openings

When the title of an article appearing in the lead paragraph requires quotation marks (for example, the title of a song or poem), the quotation marks should not be in boldface, as they are not part of the title:

• Modèle:Correct “Jabberwocky” is a nonsense poem by Lewis Carroll.

Block quotes

We use quotation marks or block quotes to distinguish quotations from other text. In the very rare case of a multiparagraph quotation that is not block-quoted, double quotes are placed at the start of each paragraph, but at the end of only the last paragraph.

Look of quotation marks and apostrophes

There are two options when considering the look of the quotation marks (that is, the glyph):

• Typographic: “text”, ‘text’, foo’s
• Typewriter: '"text", ''text'', foo''s

When quotation marks or apostrophes appear in article titles, there is a redirect to the same title using the other glyph.

Other matters

• An entire quotation is not italicized solely because it is a quotation.
• The sentence-initial letter of a quote may be lowered if the quote starts in the middle of a sentence. Where this occurs, “[i]t is unnecessary to indicate this change with square brackets”.
• Wikipedia does not use grave or acute accents or backticks (`text´) as quotation marks or apostrophes.
• If a word or phrase appears in an article in singlequotes, such as 'abcd', Wikipedia's search facility will find that word or phrase only if the search string is also within single quotes. Avoiding this complication is an additional reason to use double quotes, for which the difficulty does not arise.
• The choice of style for the quotation marks (see last heading) affects searching in an article using the local browser's facility. For example, searching in an article for "this with its quotes" will fail to find “this with its quotes”. The same applies to the style chosen for apostrophe (’ or ').

Brackets

A bracketed phrase is enclosed by the punctuation of a sentence (as shown here). (But one or more sentences wholly inside brackets have their punctuation inside the brackets.) These rules apply to square “[ ]” as well as round “( )” brackets (parentheses). There should never be a space next to the brackets on the inside, except as in the preceding sentence. There should be a space before an opening bracket, except in certain rare cases involving editorial interpolation and the like, when it is preceded by:

• an opening quotation mark

He rose to address the meeting: “(Ahem...) Ladies and gentlemen, welcome!”

• another opening bracket (see below)

Several companies ([ten omitted for brevity] GMH, Ford, and Mazda) resisted.

• an ellipsis not followed by a space, or an unspaced em dash

Well…(how could I continue?).

• a portion of a word, or a hyphen, etc., where the brackets enclose only a part of a word

We went on the Inter[continental].

There should be a space after a closing bracket, except where another punctuation mark (other than an apostrophe or a hyphen) follows, and except in cases similar to those listed for opening brackets.

If sets of brackets must be nested, use the contrasting type (normally square brackets appear within round brackets [parentheses]). Or reduce clutter by appropriate use of commas, semicolons, colons, em dashes, or spaced en dashes, rather than brackets.

Avoid adjacent sets of brackets—either put the parenthetic phrases in one set separated by commas, or rewrite the sentence. For example, this sentence:

• Modèle:Bad Nikifor Grigoriev (c. 1885–1919) (also known as Matviy Hryhoriyiv) was a Ukrainian insurgent leader.

would be better written as either of these:

• Modèle:Good Nikifor Grigoriev (c. 1885–1919), also known as Matviy Hryhoriyiv, was a Ukrainian insurgent leader.
• Modèle:Good Nikifor Grigoriev (c. 1885–1919) was a Ukrainian insurgent leader. He was also known as Matviy Hryhoriyiv.

Serial commas

The serial comma (also known as the Oxford comma or Harvard comma) is a comma used immediately before a conjunction in a list of three or more items. The phrase “ham, chips, and eggs” is written with a serial comma, but “ham, chips and eggs” is not. Sometimes omitting the comma can lead to an ambiguous sentence, as in this example: “The author would like to thank her parents, Sinéad O’Connor and President Bush.” Sometimes including the comma can also lead to an ambiguous sentence, as in: “The author would like to thank her mother, Sinéad O’Connor, and President Bush” which may be a list of either two or three people. In such cases, there are three options for avoiding ambiguity:

• A choice can be made whether to use or omit the comma after the penultimate item in such a way as to avoid ambiguity.
• The sentence can be recast to avoid listing the items in an ambiguous manner.
• The items in the list can be presented using a formatted list.

If the presence of the final serial comma does not affect ambiguity of the sentence (as in most cases), there is no Wikipedia consensus on whether it should be used.

Some style authorities support a mandatory final serial comma. These include Fowler’s Modern English Usage (Brit.), the Chicago Manual of Style (Amer.), and Strunk and White’s Elements of Style (Amer.). Others recommend avoiding it where possible; these include The Times (Brit.), The New York Times (Amer.) and The Economist (Brit.). See serial comma for further authorities and discussion.

Proponents of the serial comma, such as The Elements of Style, cite its disambiguating function and consistency as reasons for its use. Opponents consider it extraneous in situations where it does not explicitly resolve ambiguity. Many non-journalistic style guides recommend its use, while many newspaper style guides discourage its use; Wikipedia, by having no consensus, allows either style and therefore enables the avoidance of ambiguity.

By convention, the names of railroads and railways do not employ the serial comma (for example, Cleveland, Cincinnati, Chicago and St. Louis Railroad). This is also the standard for law firms and similar corporate entities (for example, Skadden, Arps, Slate, Meagher & Flom).

Colons

Colons (:) should not have spaces before them:

• Modèle:Correct He attempted it in two years: 1941 and 1943
• Modèle:Not correct He attempted it in two years : 1941 and 1943

Colons should have complete sentences before them:

• Modèle:Correct He attempted it in two years: 1941 and 1943
• Modèle:Not correct The years he attempted it included: 1941 and 1943

Dashes

The hyphen (-) is used to form compound words. The en dash (–) is used to specify numeric ranges, such as “open 9–5”. The em dash (—) can be used to link clauses of a sentence—like this one—as can the spaced en dash ( – ). Other dashes, notably the double-hyphen (--), should be avoided.font differences^{[Information douteuse]}

Spaces after the end of a sentence

There are no guidelines on whether to use one space after the end of a sentence, or two (French spacing), but the issue is not important as the difference shows up only in the edit box.

Contractions

In general, formal writing is preferred. Therefore, avoid the use of contractions—such as don’t, can’t, won’t, would’ve, they’d, and so on—unless they occur in a quotation. However, we are not reproducing the style of the 1911 Britannica; if the full form would be clumsy or unidiomatic, use the contraction or recast the sentence.

Slashes

Avoid joining two words by a slash, as it suggests that the two are related, but does not specify how. It is often also unclear how the construct would be read aloud. There is almost always a better choice than a slash. Where possible, spell things out to avoid uncertainties.

An example: “The parent/instructor must be present at all times.” Must both be present? (Then write and say “the parent and the instructor”.) Must at least one be present? (Then write and say “the parent or the instructor”.) Is it intended that the same person is both parent and instructor? (Then use an en dash, or perhaps a hyphen: “the parent–instructor”.)

In circumstances involving a distinction or disjunction, the en dash is usually preferable to the slash, e.g., “the novel–novella distinction”.

However the slash does have some legitimate uses:

• to separate run-in lines of poetry (“To be or not to be: that is the question: / Whether ’tis nobler in the mind to suffer / The slings and arrows of outrageous fortune”);
• to show pronunciations (“ribald is pronounced /ri-bəld/”);
• to separate the numerator and denominator in a fraction (“⁷⁄₈”).

“And/or”

The construct and/or is considered awkward. In general, where it is important to mark an inclusive or, use “x or y, or both”, rather than “x and/or y”. For an exclusive or, use “either x or y”, and optionally add “but not both”, if it is necessary to stress the exclusivity.

Where there are more than two possibilities presented, from which some combination is to be selected, it is even less desirable to use and/or. With two possibilities, at least the intention is clear; but with more than two it may not be determinate (see The Cambridge Guide to English Usage, 2004, p. 38). Instead of “x, y, and/or z”, use an appropriate alternative: “one or more of x, y, and z”; “some or all of x, y, and z”; etc.

Ellipses

An ellipsis is a series of three dots (periods) indicating omitted text. The precomposed ellipsis character (…, …) may be used: it displays three dots. To prevent the ellipsis from wrapping to the beginning of a line, regardless of where the line breaks of the reader’s browser fall, enter a non-breaking space before it ( …). Many style-guides recommend that a space be inserted either side of the ellipsis, except where the first portion of text itself ends with a period; in this case, four dots rather than three typically follow the last word, without an intervening space.

Examples: in the middle of your sentence … or after your comma, … or before one…, or at the end of your sentence…. In your question…? Or even your exclamation…!

Note that square brackets indicate editorial replacements as well as editorial insertions. For example, suppose that a source says, “X contains Y. Under certain circumstances, X may contain Z as well.” Then it is correct to quote this work as saying “X contains Y [and sometimes] Z” (without ellipsis).

Question marks and exclamation marks

The question mark is to be used in the standard English manner: every direct question requires a question mark; the question mark normally—though not always—marks the end of a sentence, so the grammar should reflect that fact; etc. There should never be a space just before a question or exclamation mark.

The exclamation mark is to be used with restraint, since it is an expression of surprise or emotion that is generally thought unsuited to scholarly or encyclopedic use. It normally—though not always—marks the end of a sentence, so the grammar should reflect that fact.

For use of these marks in association with quotation marks, see the relevant section above.

Clusters of question marks alone, or exclamation marks alone, or some combination of these (such as the interrobang, whether forming one character or written as an exclamation followed by a question mark) are inappropriate for use in Wikipedia articles.

Pronunciation

Pronunciation in Wikipedia is indicated using the International Phonetic Alphabet (IPA). For ease of understanding, fairly broad IPA transcriptions are usually used.

Scientific style

• For units of measure, use SI units as the main units in science articles, unless there are compelling historical or pragmatic reasons not to do so (for example, Hubble’s constant should be quoted in its most common unit of (km/s)/Mpc rather than its SI unit of s⁻¹). For other articles, Imperial, U.S. customary, or metric units may be used as the main units of measurement. See Wikipédia:Manual of Style (dates and numbers)#Units of measurement for further guidance. The Wikipedia rule for commas and periods in numbers is, for example 12,345,678.901—contrary to Continental style.
• In articles about chemicals and chemistry, use the style of the International Union of Pure and Applied Chemistry (IUPAC) for chemical names wherever possible except in article titles, where the common name should be used if different followed by mention of the IUPAC name. For general information see systematic name, and for organic compounds in particular see IUPAC nomenclature.
• In periodic table groups, use the IUPAC names (these use Arabic numerals, not Roman numerals or letters).
• For mathematics and mathematical formulae, see Wikipédia:WikiProject Mathematics.

Simple tabulation

Lines that in the editing window start with blank spaces are displayed boxed and in a fixed-width font, for simple tabulation. A line that contains only a blank space inserts a blank line into the table.

For a complete guide to more complex tables see Meta:Help:Table.

Usage and spelling

Usage

• Possessives of singular nouns ending in s should generally maintain the additional s after the apostrophe. However, if a form without an s after the apostrophe is much more common for a particular word or phrase, follow that form, such as with “Achilles’ heel” and “Jesus’ tears”.
• Abbreviations of Latin terms like i.e., e.g., or n.b., or use of the Latin terms in full, such as “nota bene”, or “vide infra”, should be left as the original author wrote them. However, articles intended for a general audience will be more widely understood if English terms such as “that is”, “for example”, or “note” are used instead.
• Use an unambiguous word or phrase in preference to an ambiguous one. For example, use “other meaning” rather than “alternate meaning” or “alternative meaning”, since alternate means only “alternating” to a British-English speaker, and alternative suggests “nontraditional” or “out-of-the-mainstream” to an American-English speaker.

Avoid first-person pronouns and one

Wikipedia articles must not be based on one person’s opinions or experiences. Thus, I can never be used except when it appears in a quotation. For similar reasons, avoid the use of we and one. A sentence such as “We should note that some critics have argued in favor of the proposal” sounds more personal than encyclopedic.

Nevertheless, it is sometimes appropriate to use we or one when referring to an experience that anyone, any reader, would be expected to have, such as general perceptual experiences. For example, although it might be best to write, “When most people open their eyes, they see something”, it is still legitimate to write, “When we open our eyes, we see something”, and it is certainly better than using the passive voice: “When the eyes are opened, something is seen.”

It is also acceptable to use we in mathematical derivations; for example: “To normalize the wavefunction, we need to find the value of the arbitrary constant A.”

Avoid second-person pronouns

Use of the second person (you), which is often ambiguous and contrary to the tone of an encyclopedia, is discouraged. Instead, refer to the subject of the sentence, for example:

• Modèle:Good When a player moves past “Go”, that player collects $200.
• Modèle:Good Players passing “Go” collect $200.
• Modèle:Good $200 is collected when one passes “Go”.
• Modèle:Bad When you move past “Go”, you collect $200.

This guideline does not apply to quoted text, which should be quoted exactly.

The guideline also does not apply to the Wikipedia namespace, where you refers to the writers to whom articles in the namespace are addressed.

National varieties of English

Cultural clashes over grammar, spelling, and capitalization are a common experience on Wikipedia. Remember that millions of people have been taught to use a form of English different from yours, including different spellings, grammatical constructions, and punctuation. For the English Wikipedia, while a nationally predominant form should be used, there is no preference among the major national varieties of English; none is more “correct” than any other. However, there is certain etiquette generally accepted on Wikipedia, as listed here. These guidelines are given roughly in order of importance; those earlier in the list will usually take precedence over later ones:

• Articles should use the same spelling system and grammatical conventions throughout.
  • Each article should have uniform spelling and not a haphazard mix of different spellings, which can be jarring to the reader. For example, do not use center in one place and centre in another in the same article (except in quotations or for comparison purposes).
  • If an article is predominantly written in one type of English, aim to conform to that type rather than provoke conflict by changing to another. (Sometimes, this can happen quite innocently, so please do not be too quick to make accusations!)
• If there is a strong tie to a specific region or topic, use the appropriate variety.
  • Proper names should retain their original spellings, for example, United States Department of Defense and Australian Defence Force.
  • Articles that focus on a topic specific to a particular English-speaking country should generally conform to the usage and spelling of that country. For example:
    • American Civil War: American English usage and spelling
    • Tolkien’s The Lord of the Rings: British English usage and spelling
    • Uluru (Ayers Rock): Australian English usage and spelling
    • European Union institutions: British, Irish and Maltese English usage and spelling
    • The city of Montreal: Canadian English usage and spelling
• Try to find words that are common to all.
  • In choosing words or expressions (especially article titles) there may be value in selecting one that does not have multiple variant spellings if there are synonyms that are otherwise equally suitable and reasonable. In extreme cases of conflicting names, a contrived substitute (such as fixed-wing aircraft) is acceptable.
  • If the spelling appears in an article name, you should make redirect pages to accommodate the other variants, as with Artefact and Artifact.
• Stay with established spelling
  • If an article has been consistently in a given variety for a long time, and there is no clear reason to change it, leave it alone. Editors should not change the spelling used in an article wholesale from one variant to another, unless there is a compelling reason to do so (which will rarely be the case). Other editors are justified in reverting such changes. Fixing inconsistencies in the spelling is always appreciated.
• Follow the variety established by the first contributor.
  • If there is no settled spelling and all else fails, consider following the spelling style preferred by the first major contributor to the article (after the article was a stub, that is).

For reference on different varieties, consult Wikipedia articles such as English plural and American and British English differences.

Finally, in the event of conflicts on this issue, please remember that if the use of your preferred version of English seems like a matter of great national pride to you, the differences are actually relatively minor when you consider the many users who are not native English speakers at all and yet make significant contributions to the English-language Wikipedia, or how small the differences between national varieties are compared with other languages. There are many more productive and enjoyable ways to participate than worrying and fighting about which version of English to use on any particular page.

Big, little, long, short

Try to use accurate measurements whenever possible. Use specific information.

Modèle:Bad	Modèle:Good
The wallaby is small.	The average male wallaby is 1.6 metres from head to tail.
Prochlorococcus marinus is a tiny cyanobacterium.	The cyanobacterium Prochlorococcus marinus is 0.5 to 0.8 micrometres across.
The large herd of dugong stretched a long way down the coast.	The dugong swam down the coast in a herd five kilometres long and 300 metres wide.

Images

Some general guidelines which should be followed in the absence of a compelling reason not to:

• Start the article with a right-aligned image.
• When using multiple images in the same article, they can be staggered right-and-left (Example: Timpani).
• Avoid sandwiching text between two images facing each other.
• Generally, right-alignment is preferred to left- or center-alignment. (Example: Race).
  • Exception: Portraits with the head looking to the reader’s right should be left-aligned (looking into the text of the article) when this does not interfere with navigation or other elements. In such cases it may be appropriate to move the Table of Contents to the right by using {{TOCright}}. Since faces are not perfectly symmetrical it is generally inadvisable to use photo editing software to reverse a right-facing portrait image; however, some editors employ this controversial technique when it does not alter obvious non-symmetrical features (such as Mikhail Gorbachev’s birthmark) or make included text in the image unreadable.
• If there are too many images in a given article, consider using a gallery.
• Do not place left-aligned images directly below second-level (===) headings, as this disconnects the heading from the text it precedes. For example, do not use:

=== Section 1b ===
[[Image:Image relating to section 1b.jpg|frame|left|]]
First paragraph of section 1b.

Instead, either right-align the image, remove it, or move it to another relevant location. If the image acts as a bridge from the previous section, you can place it at the end of that section:

[[Image:Image relating to section 1a and section 1b.jpg|frame|left|]]
=== Section 1b ===
First paragraph of section 1b.

• Use {{Commons}} to link to more images on Commons, wherever possible.
• Use captions to explain the relevance of the image to the article.
• Specifying the size of a thumb image is not recommended: without specifying a size the width will be what the reader has specified in their user preferences, with a default of 180px (which applies for most readers). However, the image subject or image properties may call for a specific image width to enhance the readability or layout of an article. Cases where specific image width are considered appropriate include:
  • On images with extreme aspect ratios
  • When using detailed maps, diagrams or charts
  • When a small region of an image is considered relevant, but the image would lose its coherence when cropped to that region
  • On a lead image that captures the essence of the article.

Bear in mind that some users need to configure their systems to display large text. Forced large thumbnails can leave little width for text, making reading difficult.

The current image markup language is:

[[Image:picture.jpg|thumb|right|Insert caption here]]

Captions

Photos and other graphics should have captions unless they are “self-captioning”, as in reproductions of album or book covers, or when the graphic is an unambiguous depiction of the subject of the article. For example, in a biography article, a caption is not needed for a portrait of the subject pictured alone; however, many entries use the name of the subject and the birth and death years and an approximation of the date when the image was taken: “John Smith (1812–95) circa 1880” or “John Smith (1812–95) on January 12, 1880 in Paris”.

Complete sentences in captions should always end in a period (or other appropriate punctuation). If the caption is not a complete sentence, it generally should not have a period at the end.

Captions should not be italicized unless they are book titles or related material. The caption always starts with a capital letter. Remember that the full information concerning the image is contained in the image entry, so people looking for more information can click on the photo to see the full details.

Bulleted lists

Do not use bullets if the passage reads easily using plain paragraphs or indented paragraphs. If every paragraph in a section is bulleted, it is likely that none should be bulleted.

Do not mix grammatical styles in a list—either use all complete sentences or use all sentence fragments. Begin each item with a capital letter, even if it is a sentence fragment.

When using complete sentences, provide a period at the end of each.

When using sentence fragments, do not provide a period at the end.

Numbered lists

All the rules for bulleted lists apply also to numbered lists.

Use numbered rather than bulleted lists only if you will be referring back to items by number, or the sequence of the items is critical (for example, you are explaining step 1, step 2, etc. of a multi-step process).

Identity

This is perhaps an area where Wikipedians’ flexibility and plurality are an asset, and where we would not want all pages to look exactly alike. Wikipedia’s neutral point of view and no original research policies always take precedence. However, here are some nonbinding guidelines that may help:

• Where known, use terminology that subjects use for themselves (self-identification). This can mean using the term an individual uses for himself or herself, or using the term a group most widely uses for itself. This includes referring to transgender individuals according to the names and pronouns they use to identify themselves.
• Use specific terminology: People from Ethiopia (a country in Africa) should be described as Ethiopian, not African.
• Do not assume that any one term is the most inclusive or accurate.
• If possible, terms used to describe people should be given in such a way that they qualify other nouns. Thus, black people, not blacks; gay people, not gays; and so forth.
• Also note: The term Arab refers to people and things of ethnic Arab origin. The term Arabic refers to the Arabic language or writing system (and related concepts). For example, “Not all Arab people write or converse in Arabic, but nearly all are familiar with Arabic numerals.”
• In a direct quotation, use the original text, even if the originator does not conform with the above guidelines.

Wikilinks

Make only links 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 up the page and make future maintenance harder. A link is the equivalent of a footnote in a print medium. Imagine if every second word in an encyclopedia article were followed by “(see:)”. Hence, the links should not be so numerous as to make the article harder to read. However, that all depends.

Check links after they are wikified to make sure they direct to the correct concept; many dictionary words lead to disambiguation pages and not to complete articles on a concept. If an anchor into a targeted page (the label after a pound sign (#) in a URL) is available, is likely to remain stable, and gets the reader to the relevant area significantly faster, then use it.

When wikilinks are rendered as URLs by the MediaWiki software, the initial character becomes capitalized and spaces are replaced by underscores. When including wikilinks in an article, there is no need to use capitalization or underscores, since the software produces them automatically. This feature makes it possible to avoid a piped link in many cases. The correct form in English orthography can be used as a straight link. Wikilinks that begin sentences or are proper nouns should be capitalized as normal.

Likewise, the use of piped links can be avoided in many cases when adding a grammatical suffix to a wikilink that is not part of an article title, by placing the suffix outside of the brackets. The suffix will still appear as part of the link, but will not be included in the link’s target when actually clicked. For example, the markup [[transformer]]s appears in the article text as transformers but links to the article named Transformer.

Miscellaneous notes

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.

In particular, do not use the CSS float or line-height properties because they break rendering on some browsers when large fonts are used.

Formatting issues

Formatting issues such as font size, blank space and color are issues for the Wikipedia site-wide style sheet and should not be dealt with in articles except in special cases. If you absolutely must specify a font size, use a relative size, that is, font-size: 80%; not an absolute size, for example, font-size: 8pt. It is also almost never a good idea to use other style changes, such as font family or color.

Typically, the usage of custom font styles will

• reduce consistency—the text will no longer look uniform with typical text;
• reduce usability—it will likely be impossible for people with custom stylesheets (for accessibility reasons, for example) to override it, and it might clash with a different skin as well as bother people with color blindness; and
• increase arguments—there is the possibility of other Wikipedians disagreeing with choice of font style and starting a debate about it for aesthetic purposes.

For such reasons, it is typically not good practice to apply inline CSS for font attributes in articles.

Color coding

Using color alone to convey information (color coding) should not be done. This is not accessible to people with color blindness (especially monochromacy), on black-and-white printouts, on older monitors with fewer colors, on monochrome displays (PDAs, cell phones), and so on.

If it is necessary to use colors, try to choose colors that are unambiguous (such as orange and violet) when viewed by a person with red-green color blindness (the most common type). In general, this means that shades of red and green should not both be used as color codes in the same image. Viewing the page with Vischeck can help with deciding if the colors should be altered.

It is certainly desirable to use color as an aid for those who can see it, but the information should still be accessible without it.

Invisible comments

Invisible comments are used to communicate with other editors in the article body. These comments are only visible when editing the page. They are invisible to ordinary readers.

Normally if an editor wants to discuss issues with other potential editors, they will do it on the talk page. However, it sometimes makes more sense to put comments in the article body, because an editor would like to leave instructions to guide other editors when they edit this section, or leave reminders about specific issues (for example, do not change the section title since others have linked here).

To do so, enclose the text which you intend to be read only by editors within <!-- and -->.

For example, the following:

Hello <!-- This is a comment. --> world.


is displayed as:

Hello world.

So the comment can be seen when viewing the wiki source (although not, incidentally, the HTML source).

Note: Comments may introduce unwanted whitespace when put in certain places, such as at the top of an article. Avoid placing comment fields in places where they might change the rendered result of the article.

Legibility

Consider the legibility of what you are writing. Make your entry easy to read on a screen. Make judicious use of devices such as bulleted lists and boldface. For more on this, see “How Users Read on the Web” by Jakob Nielsen.

External links

Links to websites outside of Wikipedia can be listed at the end of an article or embedded within the body of an article.

List of links

The standard format for a list of links is to have a header named == External links == followed by a bulleted list of links. External links should summarize the website’s contents, and indicate why the website is relevant to the article. For example:

*[http://www.aidsnews.org/ AIDS treatment news]

When wikified, the link will appear as:

• AIDS treatment news

By adding the <span class="plainlinks"></span> attribute around the above link, the resulting hyperlink will look tidier:

• AIDS treatment news

Embedded links

External links can be embedded in the body of an article to provide specific references. These links have no description other than an automatically generated number. For example:

Sample text [http://www.example.org].

When wikified, the link will appear as:

Sample text [1].

An embedded external link should be accompanied by a full citation in the article’s References section.

Footnotes

The References or Notes section can have a code which will copy your embedded link (with its external link, description, or quote), into the References or Notes section and make it a functioning link there. Do not use this code with an embedded link alone; use it only if you are adding a citation or description of the link. Here is a demonstration:

The embedded link format can look like this:

<ref name="test1">[http://www.example.org/ The name of your external link goes here.] Further explanation can go here.</ref>

It will produce this:

In the “References” section the code can look like this:

<references />

It will produce this copy of the embedded link you have made above:

You may also use the template (tl) which produces the same as above with smaller font size. For a two-column layout, use {{reflist|2}}.

Note: The code will place all properly formatted references on the page here.

Submanuals

Abbreviations Biographies Capital letters Command-line examples Dashes Dates and numbers Disambiguation pages Headings Infoboxes Latter Day Saints Legal

Links Lists of works Mathematics Medicine Music National varieties of English Pronunciation Spelling Text formatting Titles Trademarks Writing about fiction

Region-specific Arabic China-related articles Ethiopia-related articles Indic-related articles Ireland-related articles Islam-related articles Japan-related articles Korea-related articles Portuguese-related articles Philippine-related articles Thailand-related articles U.S. state highways

See also

• Style guide, the Wikipedia entry on style guides. Contains links to the online style guides of some magazines and newspapers.
• Wikipédia:Annotated article is a well-constructed article, with annotations that explain why.
• Wikipédia:Avoiding common mistakes gives a list of common mistakes and how to avoid them.
• Wikipédia:Be bold in updating pages should define your attitude toward page updates.
• Wikipédia:Citing sources explains process and standards for citing references in articles.
• Wikipédia:Editing policy explains Wikipedia’s general philosophy of editing.
• Wikipédia:Guide to layout is an example of how to lay out an article.
• Wikipédia:How to edit a page is a short primer on editing pages.
• Wikipédia:Introduction is a gentle introduction to the world of Wikipedia.
• Wikipédia:Perfect stub article shows what you should aim for at a minimum when starting a new article.
• Wikipédia:Policies and guidelines is the main stop for policies and, well, guidelines.
• Wiki markup explains the mechanics of what codes are available to you when editing a page, to do things like titles, links, external links, and so on.
• Wikipédia:WikiProject sets out boilerplates for certain areas of knowledge.
• Meta:Reading level (discussion)

References

Modèle:Writing guides

Wikipédia:Conventions de style