I tend to not use the word ‘the’ in front of acronyms, but I see this used in documents more and more.

REIP provides regional outreach services to Northeastern Ontario.


The REIP provides regional outreach services to Northeastern Ontario.

If the word ‘program’ is added after REIP, I would use ‘the.’

Which is correct?

  • 2
    It varies enormously, and for no apparent reason. Whilst we talk about 'the BBC', 'the UN', 'the CBI', 'the NHS' etc. and the Americans talk about 'the FBI', we also refer to NATO, NASA and plenty of others which don't attract an article. On a previous post there is a considerable list of both types.
    – WS2
    Dec 3, 2014 at 17:36
  • 4
    In general, I'd use "the" with initialisms (e.g., the FBI: "eff-bee-eye") and no article with acronyms (e.g., NATO: "naytoh"). I don't know if there's a formal rule for this.
    – apsillers
    Dec 3, 2014 at 17:38
  • Another example are network protocols: E.g. the transmission control protocol (TCP) and the internet protocol (IP). They are not pronounced as words but still used without an article in their abbreviated form. E.g. you can say (or write) "In that communication, TCP is used as the transport protocol" (with TCP: "tee-cee-pee")
    – Jan
    Dec 11, 2020 at 15:49
  • But network protocols are generally used weirdly: You can even write and say things like: "The TCP protocol is in another layer than the IP protocol." Where you actually say, when you expand the abbreviations directly: "the transmission control protocol protocol is in another layer than the internet protocol protocol"
    – Jan
    Dec 11, 2020 at 16:11

3 Answers 3


In my experience, this comes down to the difference between acronyms and initialisms. Acronyms are pronounced as a words, while initialisms have each of their letters pronounced individually.

I would expect to hear the FBI, because FBI is an initialism (aloud: "eff-bee-eye"). Whenever its full form (Federal Bureau of Investigation) is normally preceded by "the," I would expect its initialized form to be as well. For organizations that do not normally have a leading "the," I probably would not expect one for its initialized form, either, but I cannot think of an example.

I would not expect to hear the NATO, even when I would expect to hear the full form as "the North Atlantic Treaty Organization", because NATO is an acronym (aloud: "nay-toh", not "enn-ay-tee-oh").

Of course, I would expect the NATO member when NATO is used an adjective to describe the member of NATO.

I have never heard a formal rule for this.

  • 6
    The formal rule is simple: NATO is a proper noun (because it is pronounced as one word) while FBI is not (because it is pronounced as separate letters).
    – Kevin
    Dec 3, 2014 at 20:35

Acronyms are abbreviations that are pronounced as words. Examples:

  • NATO (North Atlantic Treaty Organization)
  • AIDS (Acquired Immune Deficiency Syndrome)

When using an acronym as a noun, should not put an article before the abbreviation.

  • REIP provides regional outreach services to Northeastern Ontario.

On the other hand, when you are using the acronym as an adjective, you then add “the.”

  • The REIP assessment was carried out last week.
  • 1
    Are these quotations from a style guide? If so, which?
    – jvriesem
    May 4, 2019 at 22:22
  • Your edit triggered an attention flag. You haven't responded to jvriesem's comment; answers are expected to have reputable references on ELU, and unattributed quotes breach copyright. Nov 1, 2019 at 17:21

As other answerers have observed, acronyms (like UNESCO) generally do not take a definite article and initialisms (like UNHCR) generally do. However, there are a number of exceptions to this rule—especially instances where initialisms appear without a definite article.

Some of the exceptions fall into recognizable categories. For example:

U.S. broadcast networks: ABC, CBS, CNN, NBC, NPR, PBS.

Corporations: AMC, AT&T, BMW, EMI, GE, GMC, IBM, PG&E, RCA, UPS

Airports whose ID codes are actual initialisms: BWI, DFW, JFK, MSP, SAT, SJC

Time zones: CST, EST, GMT, PDT

Government programs: AFDC, SDI

Common noun phrases: DNA, ESL, ESP, GAAP, HIV, HR, LPG, LSD, OCR, OJ, PR, PT, RNA, TKO

Although acronyms that normally take a definite object are much rarer, they do exist. One example is "the NASDAQ" (referring to the composite index of a U.S. stock exchange whose acronym is NASDAQ); another is "the OGPU" (a Soviet-era predecessor to Russia's FSB and SVR).

None of this is to say that the general rule that acronyms generally appear without "the" and that most initialisms—at least of proper names—are preceded by "the" is bogus. But the rule is not universally applicable, so it's wise to see how other people tend to express a particular initialism/acronym to confirm whether it follows the rule or stands as an exception to it.


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