It being the 30th anniversary of the first email spam, I thought I'd read about its history. Fascinating really. Did you know it's now ten years since the word first appeared in the OED with its electronic meaning?! Does that make you feel old?
History of SPAM

This page also led me to a lovely neologism - backronym/bacronym (or retronym) - Backronym

Then there is the real thing of course, which is also very amusing: Spam itself
...including this lady who must come from Jackieville, where Spam has two syllables: Spayam

A backronym is not a retronym. A backronym is something along the lines of Port Out Starboard Home for the origin of posh. A retronym is the addition of an adjective for the purpose of discriminating between types to a noun phrase that previous did not need one. Examples would be acoustic guitar or analog watch.

Maybe it is, but it can also be a synonym of backronym. "The word retronym also refers to an acronym constructed after the fact (a backronym)," - wikipedia

yet another example of wiki getting it wrong.

Yeah, I never heard it used that way, so it must be wrong. I suppose if anyone can find it used that way in the wild.

Addendum:

Wikipedia has a list of retronyms. Not one of them fits the disputed definition.

Who cares, it's a neologism anyway. What it will eventually become it hasn't yet. Come back in 20 years time and see what the dictionaries say then. There is nothing in the etymology of the word that precludes it meaning either of those definitions. You can use it how you like. Personally I will probably never use the word either way anyway in general conversation.

Well if it really is wrong, then correct it. That's the beauty of wikipedia. It's very democratic, which is why it is surprisingly accurate - over time by a dialectic process factual data begins to approach truth. But this particular question may be more a matter of opinion more than fact.

>more a matter of opinion more than fact.

in this case I fear that it's just poor research. if you look at the reference for the re-engineered acronym def'n, it merely cites one guy who (I'd say incorrectly) used it that way. OTOH the "authority" here is the fellow who originally coined it - he better than most knows what he meant. "The term was coined by Frank Mankiewicz[1] and popularized by William Safire[2] in 1980 in The New York Times."

here's the link to Safire's column.

I don't wiki myself, but there's the real deal, and here's Quinion's take, as well.

It still seems to me that a bacronym is a kind of retronym. Similar concept, just applied to acronyms instead of phrases (or more usually adjective-noun combinations). I think bacronym will become accepted as a subset of retronym. No reason it shouldn't. In fact, it raises the interesting possibility that if the definition of retronym is expanded or broadened, that retronym may itself become retronymised. It could become a non-acronymic retronym.

I'd like to hear your reasoning behind deciding that the two things are similar.
Retronym = At one time, all guitars were not electric. Some one invents an electric guitar. For a while, you have guitars and "electric guitars". At a later time, guitar comes to mean "electric guitar", so you have guitars and "acoustic guitars" instead.
Backronym = The Pook means The Person Of Obscure Knowledge. (unless I guessed that right ;-) ).

Jackieville, where Spam has two syllables: Spayam ! Yeah, spam has two syllables. I've also been meaning to report here that the other night our organist told us about one time when she was teaching in an elementary school, she was walking down the hall when she overheard a second-grade (i.e., 7-yr.-olds) teacher giving a spelling lesson. The word was "it". The teacher said, "Listen to the sounds of the letters. This word has two syllables: ee-ut."

You didn't, it's impossible to guess the orgin of The Pook, but I like that. Perhaps I should adopt it. However, it is not strictly speaking a bacronym, since like the programming language Perl, Pook has never actually been an acronym.