I freaking hate prescriptive linguistics. The people who love to prescribe are so often prescribing incorrectly. I couldn't get past the first one in this article:
> Acronym: this is a word, like radar or NATO, not a set of initials, like the BBC or the IMF.
Wikipedia:
> In 1943, Bell Laboratories coined the term acronym as the name for a word (such as SONAR) created from the first letters of each word in a series of words (such as SOund Navigation And Ranging). The terms initialism and alphabetism are neither widely used nor widely known. The term acronym is widely used to describe any abbreviation formed from initial letters.
First off, the word was created by a corporation; secondly, the term is widely used and understood to apply to words like "BBC" ("Three Letter Acronym"); thirdly, the "correct" alternative is not widely used or understood. So if you use the correct terms your communication would actually be less clear, which is, as I understand, the point of studying grammar/linguistics in the first place.
For more on this exciting subject, see David Foster Wallace's excellent "Democracy, English, and the Wars over Usage":
http://instruct.westvalley.edu/lafave/DFW_present_tense.html