Wikipedia:Manual of Style/Abbreviations

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This guideline covers the use of abbreviations – including acronyms and initialisms, contractions, and other shortenings – as used in the English Wikipedia.

Maintaining a consistent abbreviation style will allow Wikipedia to be read, written, edited, and navigated more easily by readers and editors alike. The style should always be consistent within a page. If a guideline conflicts with the correct usage of a proper name, ignore it. The abbreviation style used in quotations from written sources should always be written exactly as in the original source, unless it is a Wikipedia-made translation.

Always consider whether it is better to simply write a word or phrase out in full, thus avoiding potential confusion for those not familiar with its abbreviation. Remember that Wikipedia does not have the same space constraints as paper.

Use sourceable abbreviations[edit]

Avoid making up new abbreviations, especially acronyms. For example, "International Feline Federation" is good as a translation of Fédération Internationale Féline, but neither the anglicisation nor the reduction IFF is used by the organisation; use the original name and its official abbreviation, FIFe.

If it is necessary to abbreviate in small spaces (infoboxes, navboxes and tables), use widely recognised abbreviations. As an example, for New Zealand gross national product, use NZ and GNP, with a link if the term has not already been written out: NZ GNP; do not use the made-up initialism NZGNP).

Full points (periods)[edit]

Modern style is to use a full point (period) after a shortening (see § Exceptions) but no full point with an acronym. In the case of an acronym containing full points between letters, it should also have a full point after the final letter. If an abbreviation ending in a full point ends a sentence, do not use an extra full point (e.g. They lived near Courtyard Sq., not They lived near Courtyard Sq..).

Contractions that contain an apostrophe (don't, shouldn't, she'd) never take a period (except at the end of a sentence, of course). They are also not used in encyclopedia content except in quotations or titles of works, as noted below. Contractions that do not contain an apostrophe almost always take a period in North American English, but the point is optional in British English: Doctor can be abbreviated Dr. in American and Canadian English, but Dr. or Dr in British English. If in doubt, or if the dot-less usage could be confusing in the context, use the point. Exceptions are symbols of units of measurement, which never use periods (see WP:Manual of Style/Dates and numbers).

Expanded forms[edit]

Do not apply initial capitals – or any other form of emphasis – in a full term that is a common noun phrase, just because capitals are used in its abbreviation. Example: use digital scanning (DS), not Digital Scanning (DS) or digital scanning (DS).


Acronyms are abbreviations formed, usually, from the initial letters of words in a phrase.


An initialism is usually formed from some or all of the initial letters of words in a phrase. An acronym is sometimes considered to be an initialism which is pronounced as a word (e.g. NATO), as distinct from the case where the initialism is said as a string of individual letters (e.g. "UN" for the United Nations); a more precise term is word acronym, since acronym by itself is also frequently inclusive of initialisms. Herein, the term acronym applies collectively to initialisms.

Do not edit-war over these terms. If using more precise terms like word acronym and initialism, please link to Acronym#Nomenclature, where they are explained for readers.

Formation and usage[edit]

  • Capitalisation: Some acronyms are written with all capital letters, some with a mixture of capitals and lower-case letters and some are written as common nouns (e.g. laser). Acronyms whose letters are pronounced individually are written in capitals. For more guidance on the capitalisation of acronyms, see Wikipedia:Manual of Style/Capital letters#Acronyms.
  • Spacing: The letters of acronyms should not be spaced.
  • Plurals: Plural acronyms are written with a lower-case s after the abbreviation, without an apostrophe, unless full points are used between the letters (e.g. ABCs or A.B.C.'s). Note that Wikipedia generally avoids using full point in upper-case acronyms.
  • Emphasis: Do not apply special style, such as SMALL CAPS, to acronyms. Do not apply italics, boldfacing, underlining, or other highlighting to the letters in the expansion of an acronym that correspond to the letters in the acronym, as in BX (Base Exchange). It is not necessary to state that an acronym is an acronym. Our readers should not be browbeaten with the obvious.

If there is an article about the subject of an acronym (e.g. NATO), then other articles referring to or using the acronym should use the same style (capitalisation and punctuation) that has been used within the main article. If no article exists for the subject acronym, then style should be resolved by considering consistent usage in source material.

Unless specified in the "Exceptions" section below, an acronym should be written out in full the first time it is used on a page, followed by the abbreviation in parentheses, e.g. maximum transmission unit (MTU) if it is used later in the article. Common exceptions to this rule are post-nominal initials because writing them out in full would cause clutter. Another exception is when something is most commonly known by its acronym (i.e., its article here is at the acronym title), in which case the expansion can come in the parenthetical or be omitted, except in the lead of its own article: according to the CIA (U.S. Central Intelligence Agency).[a]

To save space in small spaces (see Use sourceable abbreviations), acronyms do not need to be written out in full. When not written out in full on the first use on a page, an acronym should be linked. An unambiguous acronym can be linked as-is, but an ambiguous acronym should be linked to its expansion. Upon later re-use in a long article, the template {{abbr}} can be used to provide a mouse-over tooltip giving the meaning of the acronym again without having to redundantly link it or spell it out again in the main text: {{abbr|CIA|U.S. Central Intelligence Agency}}, giving: CIA.

For partial acronyms formed using the now-rare convention of including whole short words in them, do not blindly "normalise" them to typical current style, but write each as found in the majority of modern reliable sources. Examples: "Commander-in-Chief" is generally abbreviated CinC on its own, but may appear in all-caps when used in a longer acronym (especially a U.S. government one) like CINCFLEET and CINCAIR. The Billiard Association of America was known as BA of A; while this should not be written as unsourceable variations like BAofA or BAA, the awkwardness of the abbreviation to modern eyes can be reduced by replacing the full-width spaces with thin-space characters: BA{{thinsp}}of{{thinsp}}A or BA of A gives BA of A, which better groups the letters into a unit.


Countries and multinational unions[edit]

For these commonly-referred-to entities, the full name does not need to be written out in full on first use, nor provided on first use in parentheses after the full name if written out.

Acronym Expansion Notes
EU European Union
NATO North Atlantic Treaty Organization
UAE United Arab Emirates
UK United Kingdom
UN United Nations Similarly for UN organisations such as UNESCO and UNICEF.
US or U.S. United States Both variants are used, but avoid mixing dotted and undotted within the same article; use "US" in articles with other national abbreviations, e.g. "UK" or "UAE". Using United States instead of an acronym is often better formal writing style, and is an opportunity for commonality. USA, U.S.A. and U.S. of A. are generally not used except in quoted material (see WP:Manual of Style#US and U.S.).
USSR Union of Soviet Socialist Republics

Ship names[edit]

Ship name prefixes like HMS and USS should not be written out in full.

Time zones[edit]

Abbreviations for time zones (e.g. GMT and UTC) should not be written out in full in times.


Acronyms in this table do not need to be written out in full upon first use, except in their own articles or where not doing so would cause ambiguity.

Acronym Expansion Notes
AD anno Domini ("in the year of our Lord") Should not be written out in full in dates and does not need to be linked. Do not use in the year of our Lord or any other translation of Anno Domini.
AIDS acquired immunodeficiency syndrome
a.k.a. or AKA also known as Should only be used in small spaces, otherwise use the full phrase. It does not need to be linked. Never use "aka". Use the {{a.k.a.}} template on first occurrence on the page to provide a mouse-over tooltip explaining the meaning: a.k.a.
AM amplitude modulation
am ante meridiem Should not be written out in full in times, and does not need to be linked. It should not be written AM or A.M.
BBC British Broadcasting Corporation
BC before Christ Should not be written out in full in dates and does not need to be linked.
BCE Before Common Era Should not be written out in full in dates.
CD compact disc
CE Common Era Should not be written out in full in dates.
DVD digital versatile disc
(or digital video disc)
Should not be written out in full and should not be linked to its expansion.
e.g. exempli gratia ("for example") Should not be italicised, linked, or written out in full in normal usage.
FM frequency modulation
HDMI high-definition multimedia interface
HIV human immunodeficiency virus
i.e. id est ("that is" / "in other words") Should not be italicised, linked, or written out in full in normal usage.
laser light amplification by stimulated emission of radiation
n/a or N/A not applicable Should not be written n.a., N.A., NA or na.
NASA National Aeronautics and Space Administration
PC personal computer Does not need to be written out in full on first use, nor provided on first use in parentheses after the full term if written out.
pm post meridiem Should not be written out in full in times and does not need to be linked. It should not be written PM or P.M.
radar radio detection and ranging
scuba self-contained underwater breathing apparatus
sonar sound navigation and ranging
TV television Generally use "TV" in most articles except historic articles and cultural or scholarly discussions, e.g. "TV show", "TV cameras", "the effects of television on speech patterns". Do not link or explain in normal usage.
USB universal serial bus

Acronyms in page titles[edit]

Acronyms should be used in a page name if the subject is known primarily by its abbreviation and that abbreviation is primarily associated with the subject (e.g. NASA; in contrast, consensus has rejected moving Central Intelligence Agency to its acronym, in view of arguments that the full name is used in professional and academic publications). In general, if readers somewhat familiar with the subject are likely to only recognise the name by its acronym, then the acronym should be used as a title.

One general exception to this rule deals with our strong preference for natural disambiguation. Many acronyms are used for several things; naming a page with the full name helps to avoid clashes. For instance, multiple TV/radio broadcasting companies share the initials ABC; even though some may be far better known by that acronym, our articles on those companies are found at, for example, American Broadcasting Company rather than ABC (American TV network).[b] A useful test to determine what an abbreviation usually refers to can be done by checking Acronym Finder or and finding the relative usage. If it is found that a particular subject is overwhelmingly denoted by an unambiguous acronym, the article title on that subject can be expressed as the acronym and a disambiguation page can be used for the other subjects.

In many cases, no decision is necessary because a given acronym has several expansions, none of which is the most prominent. Under such circumstances, an article should be named with the spelled-out phrase and the acronym should be a disambiguation page providing descriptive links to all of them. See, for example, "AJAR", which disambiguates between "African Journal of AIDS Research" and "Australian Journal of Agricultural Research". A title like AJAR (African journal) should be avoided if at all possible. If the acronym and the full name are both in common use, both pages should exist, with one redirecting to the other (or as a disambiguation page).

Acronyms as disambiguators[edit]

To save space, acronyms should be used as disambiguators, when necessary. For example, "Georgia (U.S. state)", "Great Northern Railway (U.S.)" and "Labour Party (UK)". The abbreviations are preferred over United States and United Kingdom, for brevity.

To help navigation, please create redirects that contain (US) and (U.S.). For example, "Great Northern Railway (US)" should redirect to "Great Northern Railway (U.S.)" (or the other way around).

Acronyms in category names[edit]


A contraction is an abbreviation of one or more words that has some or all of the middle letters removed but retains the first and final letters (e.g. Mr and aren't). Missing letters are replaced by an apostrophe in multiple-word contractions. Contractions such as aren't should not be used in Wikipedia. The contraction o'clock is an exception, as it is mandatory in all forms of writing. Certain placenames may use particular contractions (see § Special considerations, below). Per the guideline on titles of people, prefix titles such as Mr, Dr, and Prof. should not be used. Prefixes of royalty and nobility often should be used, but not in abbreviated form. (For article titles, see: Wikipedia:Naming conventions (people) § Titles and styles; and Wikipedia:Naming conventions (royalty and nobility) § Notes.)


For initials in biographical names, see Wikipedia:Manual of Style/Biographies § Initials.


A shortening is an abbreviation formed by removing at least the last letter of a word (e.g. etc. and rhino), and sometimes also containing letters not present in the full form (e.g. bike). As a general rule, use a full point after a shortening that only exists in writing (e.g. etc.) but not for a shortening that is used in speech (e.g. rhino). In general, a full form is as acceptable as a shortened form, but there are exceptions e.g. etc. should be used over et cetera. Uncommon, non-obvious shortenings should be explained or linked on first use on a page.

Song-writing credits[edit]

Outside of prose, trad. and arr. may be used in song-writing credits to save space. On first usage, use {{trad.}} and {{arr.}}, which will display a mouse-over tooltip expanding the abbreviation.

Miscellaneous shortenings[edit]

Shortening Expansion Notes
approx. approximately It should only be used in small spaces. It does not need to be linked.
c. circa ("around") In dates, to indicate around, approximately, or about, the unitalicised abbreviation c. is preferred over circa, ca, ca., approximately, or approx. It should not be italicised in normal usage. The template {{circa}} may be used.
cf. confer ("compare" / "consult") It should be linked on first use.
Co. Company It should only be used in the names of companies (like: "PLC", "LLC", "Inc.", "Ltd.", "GmbH" etc.), and can usually be omitted unless an ambiguity would result. It does not need to be linked.
ed. (eds.) edition/editor (editions/editors) This shortening (and its plural contraction) should only be used in references. It does not need to be linked.
et al. et alii ("and others") It should normally only be used in references and where it is part of a name, such as of a legal case, e.g. United States v. Thompson et al.
fl. floruit ("flourished") It should be linked on first use. Do not use flor. or flr.
lit. literal or literal translation
rev. revised It should only be used in references. It does not need to be linked.
vs./v./v versus (against / in contrast to) They do not need to be linked. Prefer "vs." except in legal contexts, where the usage is "v." or "v", depending on jurisdiction. They should not be italicised since they have long been assimilated into the language as an English word. The full word should be used in most cases, but it is conventional to use an abbreviation in certain contexts, including law and sports.
viz. videlicet ("that is to say" / "namely") It should be linked on first use.


Unit symbols[edit]

Miscellaneous symbols[edit]

  • The ampersand (&), a replacement for the word and, should only be used in small spaces such as tables and infoboxes, but, preferably, should be avoided even there. However, it is common in many trademarks and titles of published works, and should be retained when found in them.

Unicode abbreviation ligatures[edit]

Do not use Unicode characters that put an abbreviation into a single character (unless the character itself is the subject of the text), e.g.: №, ㋏, ㎇, ㉐, Ⅶ, ℅, ™︎. These are not all well-supported in Western fonts. This does not apply to currency symbols, such as ₨ and ₠.

Latin abbreviations[edit]

In normal usage, abbreviations of Latin words and phrases should be italicised, except AD, c., e.g., etc. and i.e., which have become ordinary parts of the English language. The expansions of Latin abbreviations should still be italicised (preferably automatically via the {{lang|la|...}} template), as with most foreign words and phrases: Anno Domini, circa, exempli gratia, et cetera, id est. These are not normally used in article prose.

Do not use &c. in the place of etc.

Abbreviations widely used in Wikipedia[edit]

Wikipedia has found it both practical and efficient to use the following abbreviations, although some can often be replaced by unabbreviated equivalents (that is for i.e., namely for viz., and so on). Versions of non-acronym abbreviations that do not end in stops (periods) are more common in British than North American English, and are always abbreviations that compress a word while retaining its first and last letters, rather than truncating. That said, US military ranks are often given without this punctuation. The Manual of Style on abbreviations, above, eschews the use of periods with acronyms. For example, use MD and PhD, not M.D. and Ph.D..

Word(s) Abbreviation
Avenue Ave.
Boulevard Blvd. or Blvd
East E. or E (use only in street addresses, not in other text)
Freeway Fwy. or Fwy (the term is not generally used outside of North America)
Highway Hwy. or Hwy (the term is not generally used outside of North America)
Motorway Mwy (the term is not generally used in North America)
Mountain Mtn. or Mtn
Mount Mt. or Mt
North N. or N (use only in street addresses, not in other text)
North East or Northeast N.E. or NE (use only in street addresses, not in other text)
North West or Northwest N.W. or NW (use only in street addresses, not in other text)
Road Rd. or Rd
South S. or S (use only in street addresses, not in other text)
South East or Southeast S.E. or SE (use only in street addresses, not in other text)
South West or Southwest S.W. or SW (use only in street addresses, not in other text)
Street St. or St
West W. or W (use only in street addresses, not in other text)
Organisation name elements
Academy Acad.
Association Assn. or Assn
Associates Assoc.
College Coll.
Company Co.
Corporation Corp.
Doing business as d.b.a. or DBA (avoid d/b/a and D/B/A; these are obsolete)
Incorporated Inc.
Institute/Institution Inst.
Limited Ltd. or Ltd
 Limited liability company (or partnership) LLC (LLP)
 Public limited company plc or PLC
Manufacturing Mfg. or Mfg
Press Pr.
Publications Pub., Pubs., Pubs
Publishing Pubg. or Pubg
University Univ., U. or Uni.
Academic degrees, professional titles, etc., used with personal names
Bachelor of Arts (Artium Baccalaureus) BA or AB
Bachelor of Laws (Legum Baccalaureus) LLB
Bachelor of Science BS or BSc
Master of Arts MA or AM
Master of Science MS or MSc
Doctor Dr. or Dr
 Doctor of Medicine (Medicinæ Doctor) MD
 Doctor of Philosophy (Philosophiæ Doctor) PhD
Honorable Hon.
 Right Honourable Rt. Hon. or Rt Hon.
Junior Jnr (not to be confused with Jr.)
Monsignor Mons., Msgr. or Msgr
Registered nurse RN
Reverend Rev. or Revd
Saint St. or St
Senior Snr (not to be confused with Sr.)
Military ranks
General Gen.
Colonel Col. or Col
Commander Cmdr., Cmdr, Cdr or Comdr
Major Maj. or Maj
Captain Capt.
Lieutenant Lt. or Lt
Master sergeant MSgt. or MSgt
Technical sergeant TSgt. or TSgt
Staff sergeant SSgt. or SSgt
Sergeant Sgt. or Sgt
Corporal Cpl. or Cpl
Private Pvt. or Pvt

Special considerations[edit]

  • Postal codes and abbreviations of place names – e.g. Calif. (California), TX (Texas), Yorks. (Yorkshire) – should not be used to stand in for the full names in normal text. They can be used in tables when space is tight but should be marked up with {{abbr}} template on first occurrence. They should not be used in infoboxes, nor in citations (except in an article using a published citation style that requires it). An exception of sorts is Washington, DC (also often written "Washington DC"), which has conventionally been called that, for clarity reasons, since long before postal codes were invented.
  • Saint (or Sainte) versus the St and St. abbreviations in placenames should follow the most common rendering found in reliable sources; this will most often match the official name of the place.


  1. ^ For whether and when to use "U.S." versus "US", see Wikipedia:Manual of Style § US and U.S.
  2. ^ For television related articles use the country adjective. See this RfC for additional information.

See also[edit]