I learned many fun abbreviations reading the personals in the local newsweekly in middle school/high school (aka the pages you were supposed to pretend weren't there, and the reason school officials were sometimes angry if they saw you with a copy on school grounds) that carried directly over to Craigslist. They used to charge by the word in the personal ad, so people got into a lot of common abbreviation habits.

The newsweeklies that used to carry personals lost a lot of ad revenue when Craigslist took over the space for free. (Some went bankrupt soon after CL added their city, even.) Unlikely that they will get that ad revenue back with CL out of the game, as many won't want to touch personals again for similar reasons to CL, and a lot of the personals space is also moved on to the Match.com/OKCupid/PlentyOfFishes of the internet.