Challenge

I suppose there could be some discussion as to what qualifies as an acronym, and what is actually an abbreviation. (Personally, I think acronym is often used when abbr is more appropriate.) Even Webster’s seems to be unclear. For example:
ac·ro·nym
n.
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.
n : a word formed from the initial letters of a multi-word name
ab·bre·vi·a·tion
n.
1. The act or product of shortening.
2. A shortened form of a word or phrase used chiefly in writing to represent the complete form, such as Mass. for Massachusetts or USMC for United States Marine Corps.
3.The form to which a word or phrase is reduced by contraction and omission; a letter or letters, standing for a word or phrase of which they are a part; as, Gen. for Genesis; U.S.A. for United States of America.
So, both USMC and U.S.A. are used as examples of an abbreviation, but also seem to meet the definition of an acronym (a word formed from the initial letters of a name.) I would use the abbr tag for these, since you don’t often refer to the Marines as the You Ess Em See, but you do refer to the Women’s Army Corps as the Whack. Likewise, you don’t often say You Ess Ay…just You Ess, or America. I think the key to acronym is that it is a word (WAC = Whack, not Double-U Ay See.)
Here’s an article by Craig Saila, arguing that darn near everything we currently wrap in an acronym tag actually (correctly) belongs in an abbr tag.
I really liked one of the comments from Craig’s article:
* : Use only with strict definition, i.e. for pronounceable abbreviations—if at all.
* : Use if: not pronounceable, always, or when in doubt.
Enjoy,
Tony

Ooops, the comment from the Craig Saila article got jacked up. It should read:
acronym : Use only with strict definition, i.e. for pronounceable abbreviations—if at all.
abbr : Use if: not pronounceable, always, or when in doubt.

More fun stuff:
Here’s the list of all acronyms and abbreviations used by the accessify.com acrobot. You’ll notice the majority are abbr’s. This might be a good reference point for any abbr and acronym arrays that are put together.
Note also that the 5th version of the XHTML working draft does not include the acronym tag at all, just abbr.
-Tony

The acrobot also has a favelet, which I am credited with writing but I still claim to know nothing at all about javascript.

@tcervo, I’d like to point out that some of the “acronyms” on that list are not really acronyms at all.
The idea of an ancronym is that the initial letters from the phrase creates a WORD….
National Aeronautics and Space Administration, NASA, is not a word, therefore not an acronym.
Coalition of Absolute Losers, or COAL, is a word, therefore an ancronym.
If the letters result in a jumble, pronouncable or not, then it’s just an abbreviation. There are come that are questionable though. Metro Area Planning Accosiation, MAPA, could be either one. But things like MHz… that’s an abreviation, not an acronym, as according to that list.
But maybe that was just the way I was taught…. a lot has changed since then.
TG

Morning!
Okay, so there is no challenge. Dang it…I should have know better. I’ll have to REALLY think hard to come up with something…
@tg
I my pea-brain, if an acronym (or abbreviation) becomes so widely used, such as “NASA” then I wonder if you actually consider that abbreviation (or acronym) to be a word? Ask the average person “What is NASA?” and they will tell you that it is a bunch of space monkeys who do the shuttle ‘n’ stuff. Then, ask them “What does NASA actually stand for?” and watch the blank stares appear on their faces.
Just adding some New Years’ Eve fun to the thread!
Craig.

Hmm,
That doesn’t tell me squat. In fact, it adds to the confusion. :p
Craig.

Ryan,
Craig Saila’s post is the most definitive of the ones I have seen. As always, this makes for some interesting discussion.
Craig.

Yeah, I like the Saila article as well, which is whyI posted it in my original comment ??
Seems to me, the first definition of abbreviation ( 1. The act or product of shortening) means that all acronyms can be considered abbreviations (but not the other way around.)
Since the W3C seems to be abandoning the acronym tag altogether, and using abbr seems to make more sense in most cases anyway, why not do something like photomatt’s script but using abbr instead of acronym? Even better (or worse, depending on your point of view), the script could wrap a span around the text so that it can be styled for IE (since Microsoft, in it’s infinite wisdom, decided to abandon the abbr tag in IE 6 in favor of just the acronym tab…exactly opposite of the W3C.)
Just a thought…
-Tony

Well, supposedly W3C is “clarifying” the role/use of acronym in the XHTML 2.0 specs. From what I’ve read this morning, your point (Tony) of using abbr is probably the best way to go. Seems like creating a span.abbr or span.acronym class as you suggest to style for IE is about the best workaround.

Oops. I missed tcervo’s link to Saila, read right past it. Sorry for the redundancy. Don’t mind me. ??
Ryan