LOL....
Makes you wonder if there's any three-letter abbreviation that hasn't been used yet somewhere?
As trivia go, there ARE 17576 of them....
I'm talking about abbreviations that are commonly used in a domain somewhere, not what we can make up among ourselves
I can't think of many "triples". We have AAA (ask your investment banker) and XXX (ask your porn merchant), but not many others.
A few Roman numerals might qualify (III, XXX, CCC, MMM ... ) but that's already getting a bit farfetched..
CJ