MOS:PROPERNOUN
Wikipedia avoids unnecessary capitalization. In English, capitalization is primarily needed for proper names, acronyms, and for the first letter of a sentence. Wikipedia relies on sources to determine what is conventionally capitalized; only words and phrases that are  are capitalized in Wikipedia.

There are exceptions for specific cases discussed below.

Do not use for emphasis

Initial capitals or all capitals should not be used for emphasis. If wording alone cannot provide the required emphasis, the  HTML element (or its  template wrapper) should be used:
Use: 
Avoid:

This includes over-capitalization for , i.e. to try to impress upon the reader the importance or specialness of something in a particular context. Introduction of a term of art may be wikilinked and, optionally, given in non-emphasis italics on first occurrence. Example: use , not .

Acronyms

On Wikipedia, most acronyms are written in all capital letters (such as NATO, BBC, and JPEG).  Wikipedia does not follow the practice of distinguishing between acronyms and initialisms; do not write word acronyms, that are pronounced as if they were words, with an initial capital letter only, e.g., do not write  as , or  as .
 Some acronyms (mostly trademarks like Yahoo! and Taser) conventionally or officially use a mixture of capitals and lower-case letters, even non-letters; for any given example, use the spelling found in the majority of reliable, independent sources (e.g., LaTeX, M&Ms, 3M, and InBev).  Do not mimic trademark stylization otherwise. 
 Non-trademarked acronyms that have become assimilated into English as everyday words may be written as common nouns when it is conventional to do so (e.g., scuba and laser, whereas ZIP Code and bank PIN are unassimilated acronyms and are capitalized as such).

Use only source-attested acronyms and initialisms; do not make up new ones (for example, the World Pool-Billiard Association is the WPA, and it is not referred to as the "WPBA").

"Also known as", when abbreviated on second or later occurrences, or in a table, should be given as  or  (whichever reads more easily in the context). Do not use , , or other unusual renderings.

Expanded forms of abbreviations

After hyphenation

In article text, do not use a capital letter after a hyphen except for terms that would ordinarily be capitalized in running prose, such as proper names, demonyms and brand names:  and , but not . Letters used as designations are treated as names for this purpose: .

All caps and small caps

Avoid writing with all caps (all capital letters), including small caps (all caps at a reduced size), when they have only a stylistic function. Reduce them to title case, sentence case, or normal case, as appropriate.
 Reduce newspaper headlines and other titles from all caps to title case – or to sentence case if required by the citation style established in the article. For example, replace the headline or title "WAR BEGINS TODAY" with  or, if necessary, .
 Reduce track titles on albums where all or most tracks are listed in all capitals. 
 Reduce court decisions from all caps. Write , even though the decision as issued read .
 Reduce proclamations, such as those for the Medal of Honor, from all capitals.
 Reduce text written in all capitals in trademarks – .
 Reduce Latin quotations and terms from all capitals, and put them in italics as non-English.  As this is a form of transliteration, the Latin  should be normalized to v or u, as appropriate, per modern conventions for rendering Latin. 
 Reduce names of companies or other trademarks from all caps to sentence case, unless they are acronyms or initialisms, even if the company normally writes them in all caps. See also Wikipedia:Manual of Style/Trademarks.
 Do not write with all capitals for emphasis; italics are preferred . In quoted material, all caps or small caps for emphasis should be replaced with italic  or, in an already italic passage, boldface (with HTML  or ).

Certain material may be written with all capitals or small capitals:
 Acronyms and initialisms ; these are given in all caps, not small caps.
 There are some exceptions on Wikipedia. Acronyms that have been fully assimilated into English as words are given in lowercase (, ), as are various Latinisms like ; .
 Some uses of small caps that are common in the house styles of particular publishers are not used on Wikipedia; the most common are for Roman numerals (use , not ) and for acronyms for eras (use , , etc., not , ).
 In religion, renderings of the Tetragrammaton () – but not of Adonai – can be formatted with the templates  and , when the distinction is important. These employ a mixture of all caps and small caps common in many Bible editions: .  Do not style these or similar words in colored text. 
 Certain citation styles (e.g. Bluebook) require that certain parts of a citation, such as author names in alphabetical reference sections, be written in small caps. If an article has been consistently using such a citation style, it should be respected, absent a consensus to change the style. For readability, this should be done with the template , which distinguishes the case of the input, giving uppercase full-size and lowercase in a readable small-caps size; this makes the output both more accessible and accurate to copy-paste:  visually produces , which copy-pastes as DeVoto. However, if such a citation style is not already established at an article, it is better avoided, as it is difficult to read and complicates the markup.
  The names of Unicode code points are conventionally given in small caps using the template  or similar. Example: . This is only done when presenting tables of Unicode data, and when discussing code point names as such. Otherwise prefer unstyled, plain-English character names (whether they coincide with code point names or not): , not .
 Textual excerpts, inscriptions, example words, and letterforms in classical Latin, Greek, and other unicase scripts may be given in all caps or preferably small caps (the template  is intended for this purpose) to reflect the letterforms of that era. This should only be done when it is contextually useful, as in linguistic material and descriptions of artifacts. Examples: letterforms at , and excerpts at Duenos inscription. This usage should preserve the original orthography to the extent possible in Unicode (e.g., use of  in Latin for both v and u).  When rendered this way, such material need not be italicized as non-English. When it is not possible to render such material as text, a photograph may prove useful, if a free one is available.
 In linguistics and philology, glossing of text or speech uses small caps for the standardized abbreviations of functional morpheme types (e.g. , [[Auxiliary verb|; this is done with the linguistics template , or by feeding a lowercase value to the generic template . On first occurrence, use a piped link around the template: . This style is not used for lexical glosses of content morphemes; these go in single quotes in a linear (inline) gloss (e.g., the English word dog in ), but no markup at all in an interlinear gloss.

Anglo- and similar prefixes

Most words with prefixes such as Anglo-, Franco-, etc., are capitalized. For example, Anglo-Saxon, Anglo-French and Anglo-Norman are all capitalized. However, there is some variation concerning a small number of words of French origin. In French, these words are not capitalized, and this sometimes carries over to English. There are variations, and since editors often refer to only one dictionary, they may unwittingly contravene  by changing a usage to that which is more common in their own national dialect. The main (but not mandatory) exceptions to the capitalization rule are the following.
 anglicism, gallicism, etc.: These words are often, but not always, capitalized. Anglicism is less likely to be capitalized in Canada.
 anglicize (anglicise), gallicize (gallicise), etc.: Anglicize is often capitalized in the US, and sometimes in other countries. Gallicize is often capitalized in the US, and usually capitalized in other countries.
 anglophile, francophile, etc.: Words in this category are usually capitalized both as nouns and adjectives, except in Canada, where they sometimes are.
 anglophone, francophone, etc.: These words are often capitalized in the US as adjectives, and usually as nouns. They are usually not capitalized in other countries, whether as nouns or adjectives.
 anglophobe, francophobe, etc.: Words in this category are usually capitalized in all countries except Canada, where they sometimes are. The same applies to anglophobic.
Romanize, Latinize, and related words are often lowercased in a linguistic context in particular, but otherwise usually capitalized; italic[s], in the typography sense, is always lowercase.

Animals, plants, and other organisms

Scientific names

Scientific names including genus and species (sometimes also subspecies, or other infraspecific names) have an initial capital letter for the genus, but not for the [sub]species (and are always italicized): ; . More specifically:
 The names of genera are always capitalized (and italicized), even when not paired with a species name: .
 The second part of a binomial species name is never capitalized, even when derived from a proper name (but is always italicized), and is always preceded by either the genus name, or a capitalized abbreviation of it if the full version has occurred previously in the same text: .
 In zoology, the same applies to the third part of a trinomial name: .
 In botany, the third part of a trinomial is preceded by an indication of rank which is not italicized: .

Cultivar and cultivar group names of plants are not italicized, and are capitalized. Cultivar names appear within single quotes: . Cultivar groups do not use quotation marks, but do include and capitalize the word "Group" in the name: . While the ICNCP has recently preferred the term "Group" (used by itself and capitalized) to refer to the cultivar group concept, please use the lower-case phrase "cultivar group" (aside from "Group" within an actual scientific name), as it is both less ambiguous and less typographically confusing to the average reader.

Orders, families and other taxonomic ranks above genus level have an initial capital letter (and are not italicized): ; . However, the English form derived from the Latin name should not be capitalized or italicized: ; .

Common names

Lower-case initial letters are used for each part of the English (common, vernacular) names of species, genera, families and all other taxonomic levels (, , , , ), except where they contain a proper name (, , ), or when such a name starts a sentence (). If interpretation could be ambiguous, use links or rewording to make it clearer.

 wikiprojects for some groups of organisms are in the process of converting to sentence case where title case was previously used. Some articles may not have been changed yet (this may still be true of some insect articles and some plant ones, as well as a few on amphibians and reptiles).

Names of groups or types

The common name of a group of species or type of organism is always written in lower case (except where a proper name occurs):
 , , , , , 

This also applies to an individual creature of indeterminate species.

Calendar items

Capitalize the names of months, days, and holidays: , , , , .
Seasons are uncapitalized () except when personified: ; .

Celestial bodies

The words Sun, Earth, Moon and Solar System are capitalized (as proper names) when used to refer to a specific celestial body in an astronomical context (; ). They are not capitalized when used outside an astronomical context, such as when referring to sunshine (), or when used in a general sense (). However, they are capitalized in personifications, as in .

Names of planets, moons, asteroids, comets, stars, constellations, and galaxies are proper names and begin with a capital letter (). The first letter of every word in such a name is capitalized ( and not ; , not ). In the case of compounds with generic terms such as comet and galaxy (but not star or planet), the generic is retained at the end of the name and capitalized as part of it (; ). However,  is a descriptive phrase, without capitalized "galaxy", and should usually be reduced to the actual name, , because that name is not ambiguous. If it is unclear what the Milky Way is in the context, consider using something clearer, like .  Do not capitalize descriptive terms that precede the name of an astronomical object: , .

Compass points

Points of the compass (north, north-east, southeast, etc.), and their derived forms (northern, southeasterly, etc.) are not generally capitalized: , . They are capitalized only when they form part of a proper name, such as .

Doubts frequently arise when referring to regions, such as eastern Spain and Southern California. If one is consistently capitalized in reliable sources (as with North Korea, Southern California or Western Europe), then the direction word in it is capitalized. Otherwise it is not, as with eastern Spain or southwest Poland. If you are not sure whether a region has attained proper-name status, assume it has not.

Follow the same convention for related forms: a person from the Southern United States is a Southerner.

Compound compass points are usually fully compounded in American English, for example northwest, while in British English they are sometimes written as separate words or hyphenated, as in north-west. This also affects names of regions such as Southeastern United States and South East England.  Finer compass points take a hyphen after the first word, regardless, and never use a space:  or , but not , , etc.

Geological periods

The names of formally defined geological periods and the rock layers corresponding to them are capitalized. Thus the  or the  are internationally defined periods of time, whereas the  is an unspecified time towards the end of the Cretaceous. Do not capitalize outside a complete formal name: thus  rather than .

Headings, headers, and captions

Use sentence case, not title case, capitalization in all section headings. Capitalize the first character of the first element if it is a letter, but leave the rest lower case except for proper names and other items that would ordinarily be capitalized in running text.
Use: 
Avoid: 

The same applies to the titles of articles, table headers and captions, the headers of infoboxes and navigation templates, and image captions and alt text. 

Linking is easier if titles are in sentence case. It is easier for articles to be merged or split if headings resemble titles.

Initial letters in sentences and list items

The initial letter in a sentence is capitalized. This does not apply if it begins with a letter which is always left uncapitalized (as in "eBay"; ), although it is usually preferable to recast the sentence.

When an independent clause ends with a dash or semicolon, the first letter of the following word should not be capitalized, even if it begins a new independent clause that could be a grammatically separate sentence:  For guidance after colons, see WP:Manual of Style § Colons.

In a list, if each item of the list is a complete sentence, then it should be capitalized like any other sentence. If the list items are sentence fragments, then capitalization should be consistent – sentence case should be applied to either all or none of the items. See WP:Manual of Style § Bulleted and numbered lists.

Items that require initial lower case 

In contexts where the case of symbols is significant, like those related to programming languages, mathematical notation (for example, the mathematical constant e is not equivalent to E), or the names of units of physical quantities or their symbols, the correct case should always be retained, even in situations where normal rules would require capitalization, such as at the beginning of a sentence. Try to avoid putting such lowercase symbols (or any non-alphabetic ones) at the start of a sentence within running text. 

Some individuals do not want their personal names capitalized. In such cases, Wikipedia articles may use lower-case variants of personal names if they have regular and established use in reliable third-party sources (for example, k.d. lang). When such a name is the first word in a sentence, the rule for initial letters in sentences and list items should take precedence, and the first letter of the personal name should be capitalized regardless of personal preference.

For proprietary names such as Adidas (written as 'adidas' by the company itself) and eBay, see , below.

If an article title begins with such a letter that needs to be in lower case (as in the above examples), use the  template or equivalent code. Note that it is not currently possible to make categories display with an initial lowercase letter in an article's category box. Hence the link to :Category:eBay at the foot of the article eBay must display as "EBay". Similarly the article title eBay will be displayed as "EBay" in the category listing.

Institutions

 Full names of institutions, organizations, companies, etc. () are proper names and require capitals. Also treat as a proper name a shorter but still specific form, consistently capitalized in reliable generalist sources (e.g.,  or , depending on context).
 Avoid ambiguous use of terms like "city"/"City" and "state"/"State" to indicate a governing body. Write clearly to indicate "the city council", the "state legislature", or "the state government".
 The word the at the start of a name is uncapitalized, regardless of the institution's own usage (  ).
 If you are not sure whether the English translation of a foreign name is exact or not, assume it is rough and use lower case (e.g., the French parliament).
 Generic words for institutions, organizations, companies, etc., and rough descriptions of them (university, college, hospital, church, high school) do not take capitals:
{|style="background:transparent"
|-
| Incorrect || (generic): || 
|-
| Correct || (generic): || 
|-
| Correct || (proper name): || 
|}
 Political or geographical units such as cities, towns, and countries follow the same rules: As proper names they require capitals; but as generic words and rough descriptions (sometimes best omitted for simplicity) they do not:

{| style="background:transparent;"
|-
|Incorrect || (generic): || 
|-
|Correct || (generic): || 
|-
|Correct || (name of legal entity): || 
|-
|Correct || ("city" omitted): || 
|- style="vertical-align: top;"
| Exception || style="vertical-align: top;" | ("City" used as shortened propername for the City of London): || style="vertical-align: bottom;" | 
|- 
|Incorrect || (generic plural): || 
|-
|Correct || (generic plural): || 
|-
|Correct || (plural legal entities): || 
|-
|}

These principles also apply to terms for the output of institutions, companies, and other organizations (act, bill, law, regulation, product, service, report, guideline, etc.).

Military terms

The general rule is that wherever a military term is an accepted proper name, as indicated by consistent capitalization in sources, it should be capitalized. Where there is uncertainty as to whether a term is generally accepted, consensus should be reached on the talk page.
 Military ranks follow the same capitalization guidelines as given under , below. For example, , but .
 Formal names of military units, including armies, navies, air forces, fleets, regiments, battalions, companies, corps, and so forth, are proper names and should be capitalized. However, the words for types of military unit (army, navy, fleet, company, etc.) do not require capitalization if they do not appear in a proper name. Thus, , but . Unofficial but well-known names should also be capitalized (, ).
 Correct: 
 Incorrect: 
 Accepted names of wars, battles, revolts, revolutions, rebellions, mutinies, skirmishes, fronts, raids, actions, operations, and so forth are capitalized if they are usually capitalized in sources (Spanish Civil War, Battle of Leipzig, Boxer Rebellion, Action of July 8, 1716, Western Front, Operation Sea Lion). The generic terms (war, revolution, battle) take the lowercase form when standing alone (; ; ).  Words such as campaign, offensive, siege, action, pocket, etc., are typically not frequently capitalized in sources, so are lowercase in Wikipedia (Bougainville campaign, American logistics in the Normandy campaign).
 Proper names of specific military awards and decorations are capitalized (, ).
 Terms such as soldier, sailor, marine, and coast guardsman are not capitalized when describing an individual or a group, but are when used as a rank (see above). 
 Correct: 
 Incorrect:

Musical and literary genres

Names of genres (such as musical or literary) are not capitalized unless they contain a proper name. For example:

Incorrect: 
Incorrect: 
Correct: 

Incorrect: 
Correct: 

Incorrect: 
Correct: 

Radio formats such as  or  are also not capitalized. Nor are dance types, genres, styles, moves, or social activities (, , , , ). Proper names, as always, are excepted: .

Dance genres and styles are treated the same; .

Proper names

In English, proper names, which can be either single words or phrases, are typically capitalized. Such names are frequently a source of conflict, especially when different cultures, using different names, "claim" someone or something as their own. (Avoid edit warring or pushing a particular viewpoint.) Wikipedia does not adjudicate such disputes, but as a general rule uses the name which is likely to be most familiar to readers of English. Alternative names often are also given, for greater clarity and fuller information.

Peoples and their languages

Names for peoples and cultures, languages and dialects, nationalities, ethnic and religious groups, and the like are capitalized, including in adjectival forms (, ).  Cultural terms may lose their capitalization when their connection to the original culture has been lost (or there never really was one). Some fairly conventionalized examples are , typographical ,  (cue-ball spin) in pool playing, , , ,  ('overly complex'). Some are more transitional and can be written either way:  of names, , lynching, and .  Always capitalized: , , , , , , , . Avoid over-capitalizing adjectival forms of such terms in other languages, most of which do not capitalize as much as English does. E.g., the book title  ('Spanish Biographical Dictionary') does not capitalize the e of . If in doubt, check how multiple high-quality reliable sources in English treat the name or phrase.

Combining forms are also generally capitalized where the proper name occurs: (, , ). Some may be fully fused and decapitalized if the name is mid-word; e.g., , , , and  are well-attested.  There is no consensus on Wikipedia for or against either form.  However, prefer  in proximity to other such terms (, etc.), else the lower-casing of Semitic may appear pointed and insulting.  Similarly, for consistency within the article, prefer  and  in an article that also uses , , and similar compounds. 
 
Where a common name in English encompasses both a people and their language, that term is preferred, as in  and  rather than  and .

Ethno-racial "color labels" may be given capitalized ( and ) or lower-case ( and ). The capitalized form will be more appropriate in the company of other upper-case terms of this sort ().  should not be used in Wikipedia's own voice, as it is ambiguous, and in the currently popular sense is informal, an Americanism, and a neologistic usage which conflicts with prior more specific senses.  The old epithets  and , plus  (in the American sense) and , are generally taken to be offensive, and should only be used in quotations.  When used in the context of direct quotations, titles of works, and organization names ("... Dr. Fu Manchu, the yellow peril incarnate in one man"; E. R. Baierlein's In the Wilderness with the Red Indians; National Association for the Advancement of Colored People; United Negro College Fund), follow the original's spelling.  The term  in reference to a specific ethnic group of Southern Africa is not a slur, and is capitalized; / is not offensive, and not capitalized.

Personal names

Personal names are the names given to people, but can be used as well for some animals (like race horses) and natural or man-made inanimate objects (like ships and geological formations). As proper nouns, these names are almost always first-letter capitalized. An exception is made when the lowercase variant has received regular and established use in reliable independent sources. In these cases, the name is still capitalized when at the beginning of a sentence, per the normal rules of English.  Minor elements in certain names are not capitalized, but this can vary by individual: , . Use the style that dominates for that person in reliable sources; for a living subject, prefer the spelling consistently used in the subject's own publications.

Place names 

Geographical or place names are the nouns used to refer to specific places and geographic features. These are treated like other proper names and take an initial capital letter on all major elements: , , . Terms for types of places and features do not take capitals: ; ; ; ; .

Religions, deities, philosophies, doctrines, and their adherents

Names of organized religions (as well as officially recognized sects), whether as a noun or an adjective, and their adherents start with a capital letter. Unofficial movements, ideologies or philosophies within religions are generally not capitalized unless derived from a proper name. For example, Islam, Christianity, Catholic, Pentecostal, and Calvinist are capitalized, while evangelicalism and fundamentalism are not.

Proper names and conventional titles referencing deities are capitalized: God, Allah, Freyja, the Lord, the Supreme Being, the Messiah. The same is true when referring to important religious figures, such as Muhammad, by terms such as the Prophet. Common nouns not used as titles should not be capitalized: , , . In biblical and related contexts, God is capitalized only when it is a title for the deity of the Abrahamic religions, and prophet is generally not capitalized. Heaven and Hell are capitalized when referring to a specific place () but lowercase in other circumstances ().

Transcendent ideas in the Platonic sense may also begin with a capital letter: Good and Truth.  However, this can often seem stilted, biased, or even sarcastic, so it is best avoided when possible (e.g., confined to directly quoted material, or used in a philosophical context in which the usage is conventional); use , not .  Nouns (other than names) referring to any material or abstract representation of any deity, human or otherwise, are not capitalized: , , ,  (not , , , , or ).

Except in direct quotation, pronouns for deities and figures of veneration are not capitalized, even if they are capitalized in scripture or according to a religious convention: , not 

The names of major works of scripture, such as the Bible, the Quran, the Talmud, and the Vedas, should be capitalized (but are often not italicized). The adjective biblical should not be capitalized. Quranic is normally capitalized, but usage varies for talmudic, vedic, etc.  Be consistent within an article.

Do not capitalize terms denoting types of religious or mythical beings, such as angel, fairy, or deva. The personal names of individual beings are capitalized as normal (). An exception to the general rule is made when such terms are used to denote races and the like in speculative fiction, in which case they are capitalized if the work capitalizes them ().

Spiritual or religious events are capitalized only when referring to proper names of specific incidents or periods ( and ; but , and ).

Doctrines, ideologies, philosophies, theologies, theories, movements, methods, processes, systems or "schools" of thought and practice, and fields of academic study or professional practice are  capitalized, unless the name derives from a proper name. E.g., lowercase republican refers to a general system of political thought (); uppercase Republican is used in reference to specific political parties with this word in their names (each being a proper-noun phrase) in various countries (). Nevertheless, watch for idiom, especially a usage that has become disconnected from the original doctrinal/systemic referent and is often lower-cased in sources (in which case, do not capitalize):  but ;  but . Doctrinal topics, canonical religious ideas, and procedural systems that may be traditionally capitalized within a faith or field are given in lower case in Wikipedia, such as , , , and .

Science and mathematics

In the names of scientific and mathematical concepts, only proper names (or words derived from them) should be capitalized: Hermitian matrix or Lorentz transformation. However, some established exceptions exist, such as abelian group and Big Bang theory. In some specialized fields, a character other than the first is considered the "first letter" for sentence- and title-case capitalization purposes.

Sports, games, and other activities 

Trademarked sports and games are capitalized like any other trademarks. Those that are published works (board games, roleplaying games, video games) are italicized like titles of other major works: , , . Non-stand-alone add-on publications, such as RPG modules and DLCs are minor works and take quotation marks. Sport and game rule books and rule sets are also capitalized, italicized works; named chapters within them take quotation marks, and may be given in sentence case or title case as appropriate for the context, as with chapters of other works.  

Terms relating to trademarked sports, games, and activities are capitalized if they are usually capitalized in the context of this activity: ability scores in Dungeons & Dragons, card names in Magic: The Gathering, etc. However, generic terms such as , , or  are not capitalized.

Sports, games, and other activities that are not trademarked or copyrighted are not capitalized (except where one contains a proper name or acronym, or begins a sentence). This includes groups of sports or games (, , ), traditional sports including modern ones (, , ), traditional games (, , ), folk and social dances and dance styles (, , ), and other such group and solo activities (, , , , , , , , ).

Likewise, venue types, sports equipment, game pieces, rules, moves, techniques, jargon, and other terms relating to sports, games, and activities are given in lower case and without special stylization such as italics (with the standard exceptions, e.g. capitalize proper names, italicize non-English words): , , , , , , ).

There are occasional, conventionalized variances, e.g.:
 The names of standard chess openings are capitalized (, ).
 The name of the game Go is capitalized.
 The , an aerial skateboarding move, is named for its inventor, Mike McGill, and would be confusing as "".
  and  are capitalized, including when used as adjectives.

Specific competition titles and events (or series thereof) are capitalized if they are usually capitalized in independent sources: , , .  Generic usage is not: , . None take italics or other special markup.

The above rules of thumb should also be applied to glossary entries; they are collectively an exception to the general practice of starting all list items with a capital letter, since upper-casing them all confuses readers as to which are proper names. 

There are also three related naming-conventions guidelines:

Various games- and sports-related wikiprojects also provide advice essays that often include topical style, naming, and layout tips. (However, many aren't well-maintained, and may conflict with some current guideline and policy wording; remember that they are essays.)

Capitalization of The

Do not ordinarily capitalize the definite article after the first word of a sentence; however, some idiomatic expressions, including the titles of artistic and academic works, should be quoted exactly, according to common usage.

{|style="background:transparent"
|-
| Correct || (generic): || 
|-
| Incorrect: || ||  (a redirect)
|-
| Correct || (title): || 
|-
| Incorrect: || ||  (a redirect)
|-
| Correct || (title): || 
|-
| Incorrect: || ||  (a redirect)
|-
| Correct || (exception): || 
|-
| Incorrect: || ||  (a redirect)
|-
| Correct: || || 
|-
| Incorrect: || || 
|-
| Correct || (exception): ||  (a specific golf tournament conventionally styled this way)
|-
| Incorrect: || ||  (a redirect from a description not a name)
|}

There are special considerations for: band names · institution names · nicknames · titles of works · trademarks.

Titles of people

In generic use, apply lower case to words such as president, king, and emperor (; ; ).
Directly juxtaposed with the person's name, such words begin with a capital letter (, not ). Standard or commonly used names of an office are treated as proper names (; ; ). Royal styles are capitalized (; ); exceptions may apply for particular offices.
For fuller details, see .

Titles of works

In English-language titles, every word is capitalized, except for articles, short coordinating conjunctions, and short prepositions. The first and last words within a title (and within a subtitle) are capitalized regardless of their grammatical role. This is known as title case. Capitalization of non-English titles varies by language. 

This is not applied to Wikipedia's own articles, which are given in sentence case: capitalize the first letter, and proper names (e.g., List of selection theorems, Foreign policy of the Hugo Chávez administration).

Trademarks

For trademarks, editors should choose among styles already in common use (not invent new ones) and, among those, use the style that most closely resembles standard English text formatting and capitalization rules. For trademarks that are given in mixed or non-capitalization by their owners (such as ), follow the formatting and capitalization used by independent reliable sources.  When sources are mixed, follow the standard formatting and capitalization used for proper names (in this case, as in most, ). The mixed or non-capitalized formatting should be mentioned in the article lead, or illustrated with a graphical logo.

Trademarks beginning with a one-letter lowercase prefix pronounced as a separate letter, followed by a capitalized second letter, such as iPod and eBay, are written in that form if this has become normal English usage for that name. For considerations relating to such items, see  above and .

Notes

References

Wikipedia Manual of Style (formatting)