EEUC : «Equipment Exceeds User Capabilities»
ESTO : «Equipment Smarter Than Operator»
ID-TEN-T — replace TEN with 10, the word reads ID10T, or idiot.
FGI : «Fucking Google It»
FTA : «From The Article»
GIYD : «Google It You Dumbass» (pronounced «GUIDE»)
GIYF : «Google Is Your Friend», or «Google It You Fucker»
GLOG : «Go Look On Google»
JFGI : «Just Fucking Google It»
JFWI : «Just Fucking Wiki It» — a derivative of JFGI found on IRC.
PEBKAC : «Problem Exists Between Keyboard And Chair»
PEGA : «Pilot Error! Go Around!»
RTFA : «Read The Fucking Article» — commonly used on Slashdot, digg and Fark, and usually said to someone who has obviously posted a comment without reading the relevant article.
RTFC : «Read The Fucking Card» — used by Magic: The Gathering players as a reminder not to make play errors based on not reading the cards.
RTFN : «Read The Fucking News»
RTFQ : «Read The Fucking Question» — sometimes used by technical instructors to prevent exam errors due to a less-than-thorough reading of the test item by the student. Also «RTMFQ».
RTFS : «Read The Fucking Source» — commonly used by programmers to other programmers or sufficiently technically aware people who would benefit from looking at the source code.
STFNG : «Search The Fucking News Group» — probably goes back at least to the advent of DejaNews in 1995. The earliest citation Google Groups has for it is March 1999.
STFW : «Search The Fucking Web» — first seen on Usenet in 1996 (may also mean «so the fuck what?»)
TFA : «The Fucking Article» — also commonly used on Slashdot and Fark to refer to the article in question.
UTFG : «Use The Fucking Google»
UTFSF : «Use The Fucking Search Function»
UTFW : «Use The Fucking Wikipedia»
UTSL : «Use The Source, Luke» — a parody on the popular Star Wars line; commonly used in linux context, where the basic or fallback type of installing software is the installation from (manually downloaded) source code instead of installing via packages.
WTFM : «Write The Fucking Manual» — seen in a post on the R-help mailing list: «This is all documented in TFM. Those who WTFM don’t want to have to WTFM again on the mailing list. RTFM.» (Barry Rowlingson, R-help, October 2003). Later used by Branden Robinson as the title of a presentation on writing man pages.