Today I learned (TIL from Today I learned) that there is an 83-page FBI Internet slang "guide" (GTIS from guide to internet slang), full of abbreviations used by trolls, nerds, or some completely ignorant, such as mentioned recently from Input.

And yes, TIL is included in the guide, but the same abbreviation has many different meanings. Of course no one actually uses BTDTGTTSAWIO (been there, done that, got the T-shirt and wore it out)… right?
According to Input, the FBI driver released the guide following a 2014 request from the Freedom of Information Act (FOIA). If you decide to check it out, you should know that it is of very poor quality, but it is still legible for the most part.
"With the advent of Twitter and other social networking sites on the Internet, the use of shorthand and acronyms has exploded," the guide said. "The DI Information Service Support Unit (IRSU from the Intelligence Research Support Unit) has compiled an extensive list of abbreviations and acronyms used on Twitter and other social networking sites, such as instant messengers, Facebook and MySpace."
It contains about 2.800 different examples of slang, which you may find "useful at work or to talk to your children and / or grandchildren".
Some of the weirdest I found:
420: Drugs
BTWITIAILWU: By the way, I think I am in love with you
DITYID: Did I tell you I'm depressed?
DBI: Douche bag index
MAP: Man-alien-predator
MSR: Mulder Scully Romance
NAK: Nursing at keyboard
PIMPL: Pee in my pants laughing
PMT: Pre-menstrual tension
SF: Surfer-friendly (low graphics website)
TBM: Tactical boyfriend mention
BFP: big fat positive (ie pregnant)
BIC: believe it comrade
FTASB: faster than a speeding bullet
DPYN: do not pick your nose
EB: eyeball
IITYWTMWYKM: if I tell you what this means you will kiss me
Some of the abbreviations included are not even internet slang. These are simple abbreviations that people use in their work, such as DNS (domain name service), and HSPDA (high speed packet data access).
Others are just misinterpretations, such as "LUL," which obviously means "lame uncomfortable laugh" and "LOLOL," which is interpreted as "lots of laughing out loud."
https://archive.org/details/FBIGuideToInternetSlang/mode/1up
