See Wikipedia:Shortcuts for redirects to the Wikipedia namespace. See Wikipedia:Edit summary legend for abbreviations in edit summary boxes.

This Manual of Style (or style guide) is to provide guidelines for the use of abbreviations and acronyms in Wikipedia articles. Adherence to the following guidelines is not required; however, usage of these guidelines is recommended. Maintaining consistency will allow Wikipedia to be read, written, edited, navigated, and used more easily by readers and editors alike.

Always consider whether an abbreviation may be better simply written out in full, thus avoiding potential confusion for those not familiar with it - we do not have the same space constraints as paper.

Acronyms as words in article titles

Acronyms should be used in page naming if the subject is almost exclusively known only by its acronym and is widely known and used in that form (e.g., NASA and radar). In order to determine the prominence of the abbreviation over the full name, consider checking how the subject is referred to in popular media such as newspapers, magazines, and other publications.

Many acronyms are used for several things; naming an article with the full name helps to avoid clashes. A useful test to determine what an acronym usually refers to can be done by checking abbreviations.com, and finding the relative usage for the acronym. If it is found that an acronym is chiefly used to refer to a particular subject, the article on that subject can be expressed as the acronym. A disambiguation page can then be created for the other subjects.

Whether the acronym or the spelled-out phrase is preferable in many particular cases is debatable, but this can work itself out with the #REDIRECT [[new page name]] command. For instance, DMCA and Digital Millennium Copyright Act have oscillated as to which is primary and which page redirects. Other less controversial pairs are MPAA versus Motion Picture Association of America and IMDb versus Internet Movie Database.

However, in many cases no decision is necessary because a given acronym has several expansions, none of which is the most prominent. Under such circumstances the articles should be at the spelled-out phrases and the acronym should be a disambiguation article providing descriptive links to all of them. See, for example, AJAR, which disambiguates between Australian Journal of Agricultural Research and African Journal of AIDS Research. If the acronym and the full name are both in common use, both pages should certainly be created, and one should redirect to the other (or be a disambiguation listing).

Acronyms as disambiguators

• To make link text follow the MoS, please use standard abbreviations as disambiguators, when necessary. For example, Great Northern Railway (U.S.) and Labour Party (UK). Abbreviations are preferred over "United States" and "United Kingdom", for brevity.
• To help editors, please create redirects that contain (US). For example, Great Northern Railway (US) should redirect to Great Northern Railway (U.S.).

Acronym usage in article body

The full name should always be the first reference in an article, and thereafter acronyms are acceptable, as long as the acronym is given as an explicit alternative early (usually in parentheses). If used, acronyms should be used consistently throughout the article. There is no hard rule about periods—in general, avoid them. In either case, a consistent format should be employed throughout the article.

Acronyms in category names

For the use of acronyms in names of categories, see discussion at Wikipedia talk:Naming conventions (categories)/Archive 7#Abbreviations: to expand or not to expand?.

Abbreviation types not included in this guideline

• Abbreviations in names of persons, see Wikipedia:Naming conventions (people)#Middle names - abbreviations of names
• Wikipedia:Naming conventions (ships), for example: RMS Queen Elizabeth 2; USS Monitor;...
• Wikipedia:Naming conventions (aircraft), for example: Douglas DC-3; Nakajima B5N;...

Widely used abbreviations in Wikipedia

In Wikipedia, abbreviations for common terms are often contained in parentheses within the head paragraph. 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).

Word(s) Abbreviation
General abbreviations
abbreviation abbr.
approximately/approximated approx.
absent without leave AWOL
amplitude modulation AM
also known as a.k.a.
Brothers Bros. (Largely British; should only be used in the names of companies that actually use it.)
circa ("around", "about", "approximately") ca., c.
Company Co. (commerce) or Coy. (military)
confer ("compare", "consult") cf.
department dept. or dept
district dist.
division div.
edition/editor (editions/editors) ed. (eds.)
et alii ("and others") et al.
et cetera ("and so forth") etc. or etc. (&c. is obsolete)
exempli gratia ("for example") e.g. or e.g.
floruit ("flourished") fl. or flor.
frequency modulation FM
gross national product/gross domestic product GNP/GDP
Her Majesty's Ship HMS
id est ("that is", "in other words") i.e. or i.e.
manufacturer/manufactory (manufacturing) mfr. (mfg.)
not applicable NA
personal computer PC
publisher (published) pub. (pubd.)
revised rev.
United States Ship USS
versus ("against", "in contrast to") v (legal), vs. or vs (sports)
videlicet ("that is to say", "namely") viz. (link only once)
volume vol.
Time
Anno Domini ("in the year of the Lord") AD or A.D.
ante meridiem ("before noon") a.m. or am
Before Christ BC or B.C.
Before the Common Era BCE
Common Era CE
Greenwich Mean Time GMT
post meridiem ("after noon") p.m. or pm
Places - generally consider using full road names
Avenue Ave. or Ave
Boulevard Blvd. or Blvd
Close Cl. or Cl
Highway Hwy. or Hwy
Latitude lat.
Longitude long.
Road Rd. or Rd
Street St. or St
Organizations
Academy Acad.
Association Assn. or Assn
Corporation Corp. or Corp
Incorporated Inc. or Inc
Institute/Institution Inst.
Limited Ltd. or Ltd
Public limited company PLC, plc, or p.l.c.
University Univ. or U.
Academic degrees, titles and ranks
Bachelor of Arts (Artium Baccalaureus) BA or B.A. (or A.B.)
Bachelor of Laws (Legum Baccalaureus) LLB or LL.B.
Bachelor of Science BS or B.S., BSc or B.Sc.
Captain Capt. or Capt
Colonel Col. or Col
Commander Cmdr., Cdr., Comdr. or Cdr
Corporal Cpl. or Cpl
Doctor Dr. or Dr
Doctor of Medicine (Medicinæ Doctor) MD or M.D.
Doctor of Philosophy (Philosophiæ Doctor) PhD or Ph.D.
General Gen. or Gen
Honorable Hon.
Junior Jr. or Jr
Lieutenant Lt. or Lt
Mister Mr. or Mr
Missus Mrs. or Mrs
Monsignor Msgr., Mons. or Msgr
registered nurse RN or R.N.
Reverend Rev. or Rev
Right Honourable Rt. Hon. or Rt Hon
Senior Sr. or Sr
Sergeant Sgt. or Sgt
Staff Sergeant SSgt. or SSgt
Technical Sergeant TSgt. or TSgt
States and organisations
European New Car Assessment Programme Euro NCAP (not EuroNCAP)
European Union EU
Inland Revenue IR
Internal Revenue Service IRS
International Atomic Energy Agency IAEA
National Aeronautics and Space Administration NASA
National Association for the Advancement of Colored People NAACP
North Atlantic Treaty Organization NATO
Organization of American States OAS
Royal Air Force RAF
Royal Navy RN
Securities and Exchange Commission SEC
Southeast Asia Treaty Organization SEATO
Union of Soviet Socialist Republics USSR
United Kingdom UK
United Nations Children's Fund UNICEF
United Nations Educational, Scientific and Cultural Organization UNESCO
United Nations (Organization) UN (UNO)
United States US (U.S. more common in American English)
United States Air Force USAF
United States Army USA
United States Coast Guard USCG
United States Marine Corps USMC
United States Navy USN
United States of America USA (use US if appropriate, U.S. more common in American English)
World Health Organization WHO
World Wide Fund for Nature WWF
Young Men’s Christian Association YMCA
Young Women’s Christian Association YWCA
Note: for abbreviations used by Wikipedians in discussion on talk pages and other non-article pages, see Wikipedia: Glossary.

Special considerations

• Current and former postal codes and abbreviations—such as TX for Texas, Calif. for California, Yorks for Yorkshire—should not be used to stand in for the full names in normal text.
• Mt. (and the British Mt) should not be used. Mount or Mountain should be spelled out in most situations. Exceptions are made for official names and registered trademarks. (Similarly "Saint" vs "St." or "St" in placenames should depend upon their official usage).
• Editors should almost invariably give the full name of something to be abbreviated the first time it is used, unless it is part of everyday speech and writing (such as "e.g.", "2 a.m.", etc.). For example, "The World Intellectual Property Organization (WIPO) is heavily involved with the Internet Corporation for Assigned Names and Numbers (ICANN). WIPO's long-standing ICANN role..."
• Abbreviations should be written in the same fashion each time they are used within the same article; "i.e." and "i.e." or "Col." and "Col" should not be alternated. Any special cases should have a natural reason (perhaps a list of officers in a joint Anglo-American taskforce) that should be obvious to the reader; stating such a reason explicitly will help other editors to maintain it.
• If a sentence ends with a dotted abbreviation, do not double the dot to signify the end of the sentence.

See also

• Wikipedia:Manual of Style#Acronyms and abbreviations
• Wikipedia:Disambiguation
• Wikipedia:Edit summary legend