"Acronyms", "Initialisms", "Alphabetisms","Abbreviations" These are terms that are *supposed* to help us make sense of the confusing world of shortened names, but fail.
Most people use the term "acronym" to apply to the whole lot, but this always leads one uptight wordie in the room to object that the term only applies to abbreviations whose letters form a new word like "scuba" or "NATO", not to mere combinations of first-letters like "IBM", "CIBC", or "TLA".
So this list is a) a compilation of such terms, with the most authoritative definition I can find, and b) a modest proposal offering a new term that may help us clean up this mess (which is FUBAR IMHO). Or not.
Clearest definition:
Noun: A word formed from the initial letters of a name, such as WAC for Women's Army Corps, or by combining initial letters or parts of a series of words, such as radar for radio detecting and ranging. - American Heritage Dictionary