A TLA is a Three-Letter Abbreviation - a string of exactly three letters that means something to somebody. Other names for this sort of TLA include Three Letter Acronym (when the three letters can be pronounced as a word) and Three Letter Code.
Unfortunately, there are only 17,576 possible TLAs, and that includes all the three-letter words such as "the" (which sometimes leads to Fun with Acronyms). By now, most of them mean more than one thing, and what comes to mind when you think of a TLA isn't necessarily what comes to somebody else's mind. (For example, there are hundreds if not thousands of people who hear "WWW" and don't immediately think of the Wicked Witch of the West.)
Thus, many pages on All The Tropes that are named after TLAs are disambiguation pages.
Since "TLA" is itself a TLA (complete with multiple meanings), this is a Self-Demonstrating Article ... and somewhat recursive.
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