Abbreviations, Acronyms, and Initialisms

Lesson Content

Inquire: Short and Sweet


Abbreviations, acronyms, and initialisms are shortened forms of longer or multiple words. They are used in writing as an effective means of saving space and delivering information more succinctly. In this lesson, we will look at the rules and guidelines surrounding abbreviations, acronyms, and initialisms.


Big Question

How do we, and should we, use abbreviations in our writing?

Watch: A Little Less, But Just As Much

Read: Using Abbreviations


DecorativeAbbreviations are shortened forms of longer words or phrases. You have probably been using abbreviations all your life without much thought. Most often, an abbreviation will be composed by combining the first letter of the word and at least one subsequent letter. Keep in mind, however, that there are exceptions. Sometimes, abbreviations include letters not found in the original word.

We use abbreviations to reference individuals.

Doctor Hilarius = Dr. Hilarius
Sergeant Pepper = Sgt. Pepper

We also use abbreviations when using street names.

10086 Sunset Boulevard = 10086 Sunset Blvd.
124 Conch Street = 124 Conch St.

Some abbreviations are found in measurements.

twelve ounces = 12 oz.
five pounds = 5 lb.

Another form of abbreviation is known as clipping or truncation. This type of abbreviation occurs when you remove one or more syllable(s) from a word.

dormitory = dorm
hamburger = burger

While most forms of clipping maintain the same spelling of the remaining letters, there are exceptions.

bicycle = bike
refrigerator = fridge


Another way to shorten a phrase is to replace it with an acronym. An acronym is created by taking the first (and sometimes second) letters of each word of a phrase and using them to compose a single, pronounceable word.

self-contained underwater breathing apparatus = scuba
radio detection and ranging = radar

Acronyms are often used as shorthand for organization or business names. Sometimes, the original name will be used interchangeably with the acronym, but at times, it is but a distant memory.

Screen Actors Guild = SAG
Government Employees Insurance Company = GEICO


Initialisms are shortened versions of words or phrases, and while similar to acronyms, are made up of the first letter of each word. However, the two differ in that, when put together, initialisms are pronounced by speaking each individual letter as opposed to a single word.

You’ll often see initialisms used for countries.

United Kingdom

Union of Soviet Socialists Republics

Initials are also used for companies.

Consumer Value Stores

United Parcel Service

Several everyday items are referred to by their initials.

Automatic Teller Machine

Personal Computer

Photograph of F. Scott Fitzgerald

With individuals, initialisms are used to shorten people’s names. You may have been required to “Initial Here” on various forms.

Albert Benson Cartwright (A.B.C.)
Norma Oswald Proctor (N.O.P.)

Some individuals may make the stylistic choice to reference themselves using an initial in place of one of their names.

Francis Scott Fitzgerald
F. Scott Fitzgerald

Kathryn Dawn Lang
K.D. Lang (usually stylized as k.d. lang)

It’s not even unheard of to use made-up initials.

Joanne Rowling
J.K. Rowling (Rowling has no middle name, but added the K for aesthetics.)

Period or No Period

Periods are used at the ends of abbreviations.

Dr., Mrs., St., Blvd., etc.

If a sentence ends with an abbreviation, do not add a second period (e.g., We arrived at the office of Susan Jones, M.D..)

Although acronyms such as scuba and radar are abbreviations, we do not place periods between the letters. This is because acronyms, while abbreviations, are pronounced as words. For abbreviations or initialisms that are pronounced by speaking the letters individually, such as FBI, NAACP, U.S.A, or U.N.I.C.E.F., you may or may not need periods between the letters.

Reflect: Periods and Initials


For initialisms (FBI, U.S.A., etc.), do you prefer to use periods between the letters or not?

Expand: Further Use of Abbreviations


Clippings — the form of abbreviation that occurs by removing an entire syllable from a word — can also be used with proper nouns. More specifically, clipping is a common method to form nicknames.

Samantha = Sam
Robert = Rob

As with clipping of common nouns, on occasion, the clipped word will have a slightly altered spelling.

Thomas = Tom
Abigail = Abby

Capitalization of Acronyms

DecorativeAre acronyms written in lowercase or uppercase letters? This is a bit of a tricky question, and there is no definitive answer. However, there is some consensus that you can follow.

If the acronym has entered the common lexicon — to the degree that it’s no longer even thought of as an acronym — then it will be lowercase.

radar, scuba

If the acronym is used for an organization, it will be capitalized.


To reiterate, the guidelines for capitalization of acronyms are ambiguous.

Lesson Resources

Lesson Toolbox

Additional Resources and Readings


An overview on abbreviations

Abbreviations and Acronyms

Further guidelines on abbreviations and acronyms

Abbreviations: Initialisms, Acronyms, and Contractions

A thorough introduction to abbreviations with plenty of examples and useful lists

Lesson Glossary


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  • abbreviation
    a shortened form of longer words or phrases
  • acronym
    an abbreviation created by taking the first letters of each word of a phrase and using them to compose a single, pronounceable word
  • initialism
    a shortened version of a word or phrase made up of the first letter of each word. Unlike acronyms, initialisms are pronounced by speaking each individual letter as opposed to a single word

License and Citations

Content License

Lesson Content:

Authored and curated by Oliver Shelton for The TEL Library. CC BY NC SA

Media Sources

DecorativeDivers, Scuba DiversJoakantPixabayCC 0
DecorativeF Scott Fitzgerald The World’s WorkWikimediaPublic Domain
DecorativeBeatles Sgt. Pepper 50th Anniversary Super Deluxe unboxingRob DiCaterinoFlickrCC BY 2.0
DecorativeYOLO SparklersKanielsePixabayCC 0

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