Abbreviation, Acronym, or Initialism: Fixing (not Mixing) Identity

American English often applies ways to shorten words and phrases for convenience and economy. This is particularly true in business, government, the military, and perhaps even more so now in texting and social media.

For those with an interest in grammar, the question can become whether we are using an abbreviation, an acronym, or an initialism (which is often confused with an acronym).

We last discussed this subject in 2008. More recently, we received reader questions and feedback about the proper use of acronyms in our article on style in the U.S. military. We thought it would be a good time to return to a relevant subject that can still sometimes be unclear.

We’ll start with a quick look at definitions as they apply to words and phrases:

  • abbreviation: a shortened or contracted form of a word or phrase, used to represent the whole, as Dr. for Doctor, U.S. for United States, lb. for pound. An abbreviation can also be a shorter word achieved by omitting letters, such as cray for crazy (sometimes heard in Millennial-speak). Acronyms and initialisms are forms of abbreviation.
  • acronym: a word formed from the initial letters or groups of letters of words in a set phrase or series of words and pronounced as a separate word, such as RAM for random access memory and OPEC for Organization of Petroleum Exporting Countries.
  • initialism: a set of initials representing a name or an organization with each letter pronounced separately, as FBI for Federal Bureau of Investigation.

In some cases, we might also see hybrids of acronyms and initialisms:

  • CD[initialism]-ROM[acronym] for compact disc read-only memory
  • J[initialism]PEG[acronym] for Joint Photographic Experts Group

These days, acronym and initialism are often referred to interchangeably, including by popular references such as and Merriam-Webster online (as well as military style guides, which we examined in A Study of Style: The U.S. Military). This contributes to the blurring of the distinction between them.

Because we aim for precision and eloquence in daily formal writing, we will reinforce how they differ by reviewing each category in its own table with some current examples.

Abbreviations (shortened or contracted to represent the whole)
approx. (approximately) est. (established) St. (Street)
dept. (department) Mr. (Mister) U.K. (United Kingdom)
e.g. (exempli gratia = for example) no. (number) vs. (versus)
Acronyms (made from first letters or groups of words, pronounced as a separate word)
ASAP (as soon as possible) NATO (North Atlantic Treaty Organization)
AWOL (absent without leave) RADAR (radio detecting and ranging)
DARE (Drug Abuse Resistance Education) YOLO (you only live once)
Initialisms (set of initials, each pronounced separately)
BTW (by the way) IMO (in my opinion)
CSI (crime scene investigation) MIA (missing in action)
ETA (estimated time of arrival) VIP (very important person)

Note that acronyms and initialisms may be punctuated if the style preference is to do so (e.g., A.S.A.P., C.S.I.). The Associated Press Stylebook, one of our main style guides, advises to “avoid alphabet soup” when writing: Do not use abbreviations [also comprising acronyms] that the reader would not quickly recognize … Names not commonly before the public should not be reduced solely to save a few words. 

It also instructs to “not follow an organization’s full name with an abbreviation or acronym in parentheses or set off by dashes. If an abbreviation or acronym would not be clear on second reference without this arrangement, do not use it.”

In other words, abbreviations, acronyms, and initialisms can help keep our content shorter and more concise, but as always, we need to know our audience. Overuse of these devices can distract, confuse, and make our content less formal than we’d like it to be. Understanding the differences among them will give us greater command of their functions in both writing and speech.

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10 Comments on Abbreviation, Acronym, or Initialism: Fixing (not Mixing) Identity

10 responses to “Abbreviation, Acronym, or Initialism: Fixing (not Mixing) Identity”

  1. Alexa says:

    What is the proper way to use represent “also known as” when giving a person’s name AND another name they use or have used?
    I have seen a/k/a, AKA, aka, a.k.a., and just about anything else one can imagine.
    I use this surprisingly often, and I can never quite decide which to use.

    • says:

      AP Stylebook writes “aka.” Chicago Manual of Style uses periods (a.k.a.). We recommend choosing a style and being consistent.

  2. Rajni Saini says:

    Established in 1933 and headquartered in Florida (the US), XYZ is a leading provider of …..
    Should it be US or the US?

  3. Slawek says:

    Could you please look at your quote and let me know whether everything is ok with that? It seems to me that something (a word/words) is missing here but I might be wrong.
    “Do not use abbreviations [also comprising acronyms] that the reader would not quickly recognize … Names not commonly before the public should not be reduced solely to save a few words.”
    Thanks and regards.

    • If you’re wondering about “Names not commonly before the public …” we understand the awkwardness you’re feeling. It is an accurate direct quote from the AP Stylebook. AP’s meaning is something to the effect “Abbreviations that the public is not generally familiar with …”

  4. Lou Guillou says:

    There may be a related category that doesn’t seem to be covered by the abbreviations, acronyms, or initialisms article. Early in my mathematics career, a colleague mentioned to me that “math” is not an abbreviation of “mathematics” since a period is not used (i.e., not “math.”). He said that it is a diminution of “mathematics.”
    Any comment about the existence and role of his diminution category?

  5. Diane Fowler says:

    On the other side of the Pacific, the practice regarding abbreviations and contractions is somewhat different.
    The discriminating point between the two is that a contraction retains the first and last letters of the word to be shortened and does not take a full stop, whereas an abbreviation uses one or more letters representing part of the word to be shortened.
    Thus we have: Doctor becomes Dr not Dr.; versus becomes v. or vs, not vs.; Street becomes St not St.; company becomes co. or coy; Mister becomes Mr not Mr.; department becomes dept not dept.
    Are you aware of other variations to this style of usage? I am fascinated and would love to find out.

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