Use of 'the’ in front of acronyms and initialisms

Solution 1:

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.

Solution 2:

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.