This Manual of Style has the simple purpose of making the encyclopedia easy to read, by establishing agreed principles for its format. It is a style guide. The following rules do not claim to be the last word on Wikipedia style. One way is often as good as another, but if everyone does things the same way, Wikipedia will be easier to read and use, and easier to write and edit. These are not rigid laws: they are principles that many editors have found to work well in most circumstances, but which should be applied with flexibility. In this vein, editors should strive to have their articles follow these guidelines.

While quality of writing may be more important than presentation and formatting, these elements also have their place in clear and unbiased delivery of information. One of the joys of wiki editing is that Wikipedia does not demand perfection. Wikipedia does not require writers to follow all or any of these rules, but their efforts will be more appreciated when they are guided by them.

If this page does not specify which usage is preferred:

• Use other reliable resources, such as the style guides listed below.
• Discuss your problems or propose missing style guidance on Wikipedia talk:Manual of Style.
• Simply look around. Open articles for editing, to see how editors have put them together.

Some examples of authoritative style guides are: The Chicago Manual of Style and Fowler’s Modern English Usage. Chicago also provides an online guide, the Chicago Manual of Style Online. Style guides available at no cost are the Mayfield Electronic Handbook of Technical & Scientific Writing and the CMS Crib Sheet by Dr. Abel Scribe.

In June 2005, the Arbitration Committee ruled that, when either of two styles is acceptable, it is inappropriate for a Wikipedia editor to change from one style to another unless there is some substantial reason for the change. For example, with respect to British spelling as opposed to American spelling, it would only be acceptable to change from American spelling to British spelling if the article concerned a British topic. Revert warring over optional styles is unacceptable; if the article uses colour rather than color, it would be wrong to switch simply to change styles, although editors should ensure that articles are internally consistent. If it has been stable in a given style, do not change it without some style-independent reason. If in doubt, defer to the style used by the first major contributor. See Wikipedia:Requests for arbitration/Jguk.

See the #National varieties of English section below for an example of such an issue.

If possible, make the article’s topic the subject of the first sentence of the article (as opposed to putting it in the predicate or in a subsequent sentence). For example, write “This Manual of Style is a style guide” instead of “This style guide is known as…”.

If the article title is an important term, use it as early as possible in the article. Use boldface for the first (and only the first) appearance of the title and any important synonyms (including acronyms). Use three apostrophes to produce the boldface: '''article title''' produces article title.

This example illustrates the use of boldface in an article on Río de la Plata:

The Río de la Plata (Spanish: “River of Silver”), also known by the English name River Plate, as in the Battle of the River Plate, or sometimes (La) Plata River....

Avoid other uses of boldface in the first paragraph, so the reader will not confuse the text with synonyms.

Avoid putting links in the boldfaced titles and synonyms.

Follow the normal rules for italics 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 the article does not have a name and the article’s 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 article, and, if it does appear, it should not be bolded:

A dynamic loudspeaker’s electrical characteristics are expressed as a curve, representing the…

Markup

Use the == (two equal signs) style markup for headings (also called section titles), not the ''' (triple apostrophes) used to make words appear boldface in character formatting. Start with ==, add the heading title, then end with ==.

This section’s heading was created with the markup:

==Sections and headings==

This subsection’s heading was created with the markup:

===Markup===

Wording

• In a heading, capitalize only the first letter of the first word and the first letter of any proper nouns, and leave all of the other letters in lowercase. Example: “Rules and regulations”, not “Rules and Regulations”.
• Avoid special characters in headings, such as a slash (/), a plus sign (+), curly braces ({}), or square braces ([]). In place of an ampersand (&) use the word and, unless the ampersand is part of a formal name.
• Avoid putting links in headings; try to link the first occurrence of the word or phrase in the section text, instead.
• Keep the heading short: headings more than ten words long may defeat their purpose.
• Avoid redundancy and unnecessary words in headings, such as articles (a, an, and the), pronouns, and repetition of the title of the whole article.
• Do not give identical titles to different sections. Doing so tends to confuse the reader, and makes it more difficult for any writer to create a section link to any such section except the first.

Section management

Sub-headings help readers get an overview of the article and find subtopics of interest. Create sub-headings if a section becomes too long, and choose appropriate sub-headings to aid in your exposition.

• If at all possible, try not to change section headings and sub-headings often. Other articles may link to a specific section. It will break the section links.
• If you link to a section, leave an editor’s note to remind others that the section title is linked. List the names of the linking articles, so when the title needs changing, others can fix the links more easily. For example: <!-- This section is linked from [[Richard Dawkins]] and [[Daniel Dennett]] --> .
• If you refer to a section without linking, italicize the section name. For example, this line is in the section on Section management.
• If you link to a section, do not italicize the section name, unless 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, you may be able to check for broken links. For example, at Google you can search for wikipedia “section management” and have a fair chance of finding links to this section.

American English and British English sometimes differ in their inclination to use capitals. If possible, as with spelling, use rules appropriate to the cultural and linguistic context. In other words, do not enforce American rules on pages about Commonwealth topics or Commonwealth rules on pages about American topics. In regard to pages about other cultures, choose either style, but be consistent within the page itself.

Initial capitals and all capitals should not be used for emphasis. For example, “aardvarks, which are Not The Same as anteaters” and “aardvarks, which are NOT THE SAME as anteaters” are both incorrect. Where wording cannot provide the emphasis, use italics (“aardvarks, which are not the same as anteaters”).

Titles

Titles such as president, king, or emperor start with a capital letter when used as a title (followed by a name): “President Nixon”, not “president Nixon”. When used generically, they should be in lower case: “De Gaulle was the French president.” The correct formal name of an office is treated as a proper noun. Hence: “Hirohito was Emperor of Japan.” Similarly, “Louis XVI was the French king” but “Louis XVI was King of France”, King of France being a title in that context. Likewise, capitalize royal titles: “Her Majesty” or “His Highness”. (Reference: Chicago Manual of Style 14th ed., 7.16; The Guardian Manual of Style, “Titles” keyword.) Exceptions may apply for specific offices.

In the case of “prime minister”, either both words begin with a capital letter or neither, except when the term begins a sentence. When using the term generically, do not capitalize it: “There are many prime ministers around the world.” When referring to a specific office, generally use uppercase: “The British Prime Minister is Tony Blair.” (A good rule of thumb is this: when the modifier is the definite article the, use “Prime Minister”; when the modifier is the indefinite article a, use “prime minister”. When there is no article, some style manuals recommend, for example, “British prime minister”.)

For the use of titles and honorifics in biographical articles, see Wikipedia:Manual of Style (biographies)#Honorific_prefixes.

Religions, deities, philosophies, doctrines, and their adherents

Names of religions, whether as a noun or an adjective, and their followers start with a capital letter. The Latter Day Saint movement has particular complications — see Wikipedia:Manual of Style (Latter Day Saints) and Wikipedia:Naming conventions (Latter Day Saints).

Names of deities begin with a capital letter: God, Allah, Freya, the Lord, the Supreme Being, the Messiah. (Note that articles such as “the” are not capitalized.) The same is true when referring to important religious figures, such as Muhammad, by terms such as the Prophet. Transcendent ideas in the Platonic sense also begin with a capital letter, as in Good and Truth. Pronouns referring to deities, or nouns (other than names) referring to any material or abstract representation of any deity, human or otherwise, do not begin with a capital letter. Thus, while it is accepted correct usage to say, “He prayed to Wotan”, since Wotan in this case is a proper name, one would not say “He prayed to the God Wotan”, but instead “He prayed to the god Wotan”. The following sentence would be correct usage: “It was thought that he prayed to God, but it turned out he prayed to one of the Norse gods.”

Do not capitalize the names of types of mythical creatures, such as elves, fairies, nymphs and genies. The exception is some works of fantasy, such as those of J. R. R. Tolkien, where initial capitals are used to indicate that the different categories of mythical creatures are being treated as ethnicities or races.

Philosophies, theories, doctrines, and systems of thought 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 (each party name being a proper noun).

Calendar items

The names of months, days, and holidays always begin with a capital letter: June, Monday, Fourth of July (when referring to the U.S. Independence Day, otherwise July 4 or 4 July).

Seasons, in almost all instances, are lowercased: “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, in which case they should be capitalized: “I think Spring is showing her colors”; “Old Man Winter”.

Dates normally should be followed by commas: “In 2001, Bob got married”; “On April 10, I will be having a party”. An exception is when they are used to modify other terms: “The 1993 edition has several errors”.

Animals, plants, and other organisms

Capitalize the name of a genus, but not the name of a species (and italicize both names): for example, the tulip tree is Liriodendron tulipifera.

Editors have hotly debated whether the common names of species should start with a capital letter, and this remains unresolved. As a matter of truce, both styles are acceptable (except for proper names), but create a redirect from the alternative form.

Celestial bodies

Names of other planets and stars are proper nouns and begin with a capital letter: “The planet Mars can be seen tonight in the constellation Gemini, near the star Pollux.” In cases where the name has multiple words, it is treated like other proper nouns where each leading letter is capitalized: “Alpha Centauri” and not “Alpha centauri”.

The words sun, earth, and moon are proper nouns when the sentence uses them in an astronomical context, but not elsewhere: so “The Sun is a main sequence star, with a spectral class of G2”; but “It was a lovely day and the sun was warm”. Note that 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”.

Directions and regions

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.

Directions (north, southwest, etc.) are not proper nouns and do not start with a capital letter. The same is true for their related forms: someone might call a road that leads north a northern road, compared to the Great North Road.

If you are not sure whether a region has attained proper-noun status, assume it has not.

Institutions

Proper names of specific institutions (for example, Harvard University, New York-Presbyterian Hospital, George Brown College, etc.) are proper nouns and require capitalization.

However, the words for types of institutions (university, college, hospital, high school, etc.) do not require capitalization if they do not appear in a proper name:

Incorrect:

The University offers programs in arts and sciences.

Correct:

The university offers… or The University of Ottawa offers…

Use the '' (italic) markup. Example:

''This is italic.''

which produces:

Effect on nearby punctuation and links

In all of the uses mentioned here, care should be taken to italicize only what should properly be affected by italics, and not the surrounding punctuation of the sentence. This is the consensus of most style manuals, including The Chicago Manual of Style, which has recently converted to this practice. Examples:

• What are we to make of that?

[Incorrect: only the word that is properly subject to emphasis.]

• The word was tack; it certainly was not tick, tap, or tab.

[Correct: the punctuation marks here are not being cited or mentioned; they are ordinary parts of the sentence.]

In linked material that is to be italicised, the italic markup should be outside of the link markup. Example:

• The opera ''[[Turandot]]'' is his best.

[Correct: it will generate text with a proper link: “The opera Turandot is his best.”]

Emphasis

Italics are mainly used to emphasize certain words. Italics for emphasis should be used sparingly.

They are also used in these other cases:

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

Use italics when writing about words as words, or letters as letters (see use-mention distinction). For example:

• Deuce means “two”.
• The term panning is derived from panorama, a word coined in 1787.
• The most common letter in the English language is e.

Foreign terms

Wikipedia prefers italics for phrases in other languages and for isolated foreign words that do not yet have common use in the English language. Use anglicized spellings for such words, or use the native spellings if they use the Latin alphabet (with or without diacritics).

Loan words or phrases that have common use in English, however—praetor, Gestapo, samurai, esprit de corps—do not require italicization. If looking for a good rule of thumb, do not italicize words that appear in an English language dictionary. Per the guide to writing better Wikipedia articles, use foreign words sparingly, and include native spellings in non-Latin scripts in parentheses. Native spellings in non-Latin scripts (such as Greek or Cyrillic) should not be italicized at all, even where this is technically feasible; the difference of script suffices.

Quotations in italics

Do not put an entire quotation in italics solely because it is a quotation.

Italics within quotations

Use italics inside quotations if the source material does, or if you want to add emphasis. If you do the latter, insert the editorial note “[emphasis added]” 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 you want to stress that the emphasis is the source’s and not yours, you can add “[emphasis in original]” after the quote.

Do not assume that your reader is familiar with the acronym or abbreviation you are using. The standard writing style is to spell out the acronym or abbreviation on the first reference (wikilinked if appropriate) and then show the acronym or abbreviation after it, in parentheses. This tells readers they will probably find it later in the text and makes it easy for them to refer back to it. 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.

If the term is already in parentheses, use or to indicate the acronym. For example:

They first debated the issue in 1992 (at a convention of the New Democratic Party or NDP).

It can also be helpful in a longer article to spell out the acronym or abbreviation for the reader again or to rewikify it if it has not been used for a while, especially at its first use in a major section.

Acronyms and abbreviations are made plural by adding -s or -es. For example:

• More than one CD-ROM are CD-ROMs
• More than one NGO are NGOs

Contemporary style omits many periods and spaces that were traditionally required. For example, PhD is preferred over Ph.D. or Ph. D., but do not omit periods from abbreviations that cannot be clearly identified as such without them.

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

Whenever it is reasonable to do so, use the style that was used in the original text; do not alter it to conform to Wikipedia punctuation. When the original style is unreasonable, indicate the changes, with [sic] or an explanation. An exception: when a quotation encloses a quotation, use the Wikipedia style of beginning with double-quotes outermost; working inward, alternate single-quotes with double-quotes. For example, you might quote an article that says, “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” ’ ”. (Note that adjacent quote marks, as at the end of this example, should always have a space between them. This should be a non-breaking space, obtained by typing &nbsp; instead of a normal space.)

Or applying this rule to a block quote (though passages this short would generally not be block-quoted), you might quote the article as saying

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’ ”.

Here are two examples from the Chicago Manual of Style that show how to handle commas and capital letters at the beginning of a quote within a sentence:

He said that “to have is to hold”.

She said, “Go now”.

Avoid linking from within quotes, as doing so clutters the quotation, violates the principle of leaving quotations unchanged, and may mislead or confuse the reader. On the other hand, consider this example (quoted from John Adams): “If Aristotle, Livy, and Harrington knew what a republic was, the British constitution is much more like a republic than an empire.” Every alternative to those links seems awkward.

Format a long quote (over four lines) as a block quotation, which Wikipedia will indent from both margins. Do not enclose the block quote in quotation marks. To format a block quotation, do not use the wiki indentation mark : – instead, use the HTML <blockquote> tag:

<blockquote>
Four score and seven years ago, our fathers brought forth on this continent a 
new nation, conceived in Liberty, and dedicated to the proposition that all men 
are created equal.
</blockquote>

Result:

Four score and seven years ago, our fathers brought forth on this continent a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.

Due to a bug in the site’s software, <blockquote> does not yet properly format multiparagraph quotes. Until this is fixed, you may work around it by manually adding <p> tags around paragraphs:

<blockquote>
<p>First paragraph</p>

<p>Second paragraph</p>
</blockquote>

Except with well-known quotations (from Shakespeare etc.), and those from the subject of the article or section, always name the person whom you quote for a full sentence or more. Name the person in the text, not in a footnote, unless the person is the subject of the article or is otherwise obvious. In the case of a famous line from a play in an article on the play, attribution is not necessary.

In most cases, simply follow the usual rules of English punctuation. A few points where Wikipedia may differ from usual usage follow.

Quotation marks

With quotation marks (inverted commas), we borrow one practice from usage in the United States and one from the rest of the English-speaking world. The guideline is to use the double-quotes (“ ”) – they are easier to read on the screen – and use single-quotes (‘ ’) for quotations nested within quotations. Adjacent quotation marks should be separated by a space, preferably a non-breaking space obtained by typing &nbsp;.

When punctuating quoted passages, put the punctuation mark inside the quotation marks only if the sense of the punctuation mark is part of the quotation (logical quotations). In the very rare case of a multi-paragraph quotation that is not block-quoted, put double-quotes at the beginning of each paragraph, but at the end of only the last paragraph.

Examples:

• Arthur said the situation is “deplorable”. (When a sentence fragment is quoted, period [full stop] is outside.)
• Arthur said, “The situation is deplorable.” (When a complete sentence is quoted, period is inside.)
• Martha asked, “Are you coming?” (When quoting a question, question mark is inside.)
• Did Martha say, “Come with me”? (When questioning a quote, question mark is outside, period is omitted.)

If you change the case of the initial letter of a quote, Wikipedia neither requires nor recommends that you follow the older convention of “[f]ormally indicating the case change with square brackets”.

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:

“Jabberwocky” is a nonsense poem by Lewis Carroll.

Use quotation marks or block quotes to distinguish quotations from other text. Quotations should not be italicized unless the material otherwise calls for italics (emphasis, use of non-English words, etc.).

Long quotations

Long quotations may be rendered as block quotations, without quotation marks or italics. A long quotation is indented by using <blockquote> </blockquote> notation, which indents both left and right margins (see #Quotations).

Look of quotation marks and apostrophes

Never use grave and acute accents or backticks (`text´) as quotation marks or apostrophes.

Quotation marks affect searching

If a word or phrase appears in an article in single-quotes, such as 'abcd', the Wikipedia:Searching facility considers the single-quotes to be part of the word and 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.

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).

If sets of brackets must be nested, use the contrasting type (normally square brackets appear within round brackets [parentheses]). Or reduce clutter by replacing brackets appropriately with commas or semicolons or colons – or em-dashes.

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

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

would be better written as either of these:

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

Correct:

He attempted it in two years: 1941 and 1943

Incorrect:

He attempted it in two years : 1941 and 1943

Dashes

The hyphen (-) is used to form compound words. The en-dash (–) is used to specify numeric ranges. The em-dash (—) can be used to link clauses of a sentence, as can the spaced en-dash ( – ). Other dashes, notably the double-hyphen (--), should be avoided.

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. See Wikipedia talk: Manual of Style archive (spaces after the end of a sentence) for a discussion on this.

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/"; and to separate the numerator and denominator in a fraction (“7⁄8”).

“And/or”

The construct and/or is especially 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 pre-composed 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 ( …).

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 ways: 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.

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 the interrobang, whether forming one character or written as an exclamation followed by a question mark) are inappropriate for use in Wikipedia articles.

• 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 Wikipedia: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 Wikipedia:WikiProject Mathematics.

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

• 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. should generally be avoided and English terms such as that is, for example, or note 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:

Good:

When a player moves past “Go”, that player collects $200.

Good:

Players passing “Go” collect $200.

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.

Cultural clashes over grammar, spelling, and capitalisation/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/dialect, use that dialect.
  • 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
    • Taj Mahal: Indian 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 in a given dialect 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 dialect of the first contributor.
  • If all else fails, consider following the spelling style preferred by the first major contributor (that is, not a stub) to the article.

For reference on different dialects, 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.

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

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. Instead, place the image directly above the heading. For example, use:

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

not:

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

• 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 in order to enhance the readability and/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

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]]

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, most 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.

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.

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).

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.

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.

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.

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 on 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 on certain places, such as 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.

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 and/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're 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: ^[1]

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

<div class="references-small"><references /></div>

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

You may also use the template {{reflist}} which produces the same as above. For a two-column layout, use {{reflist|2}}.

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

• Style guide, the Wikipedia entry on style guides. Contains links to the online style guides of some magazines and newspapers.
• Wikipedia:Annotated article — the article contains annotations that show how it should be edited preferentially.
• Wikipedia:Avoiding common mistakes gives a list of common mistakes and how to avoid them.
• Wikipedia:Be bold in updating pages should define your attitude toward page updates.
• Wikipedia:Citing sources explains process and standards for citing references in articles.
• Wikipedia:Editing policy has even more editing guidelines.
• Wikipedia:Guide to layout is an example of how to lay out an article.
• Wikipedia:How to edit a page is a short primer on editing pages.
• Wikipedia:Introduction is a gentle introduction to the world of Wikipedia.
• Wikipedia:Perfect stub article shows what you should aim for at a minimum when starting a new article.
• Wikipedia: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.
• Wikipedia:WikiProject sets out boilerplates for certain areas of knowledge.
• Meta:Reading level (discussion)