http://www.catb.org/jargon/html/T/TLA.html

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The self-effacing phrase “TDM TLA” (Too Damn Many...) is often used to bemoan the plethora of TLAs in use. In 1989, a random of the journalistic persuasion asked hacker Paul Boutin “What do you think will be the biggest problem in computing in the 90s?” Paul's straight-faced response: “There are only 17,000 three-letter acronyms.” (To be exact, there are 26^3 = 17,576.) There is probably some karmic justice in the fact that Paul Boutin subsequently became a journalist.