I've seen "OTL" being used around the internet in forums and social networking sites and the like...I only today did I realise that in most contexts it is not actually an acronym but an emoticon...OTL much?

So I was wondering, have there been any weird internet slang, terminology or acronyms that took you a while to find out? Or did you already know to refer to urban dictionary or some other 'reliable' resource to find out?

I know for me, it took me a while to realise that "jk" was supposed to be an acronym for "just kidding" and not an abbreviation of the word "joke", fortunately the context fit either way for that misunderstanding...and "LMAO" was also another one that took me longer than it should've for me to find out, through asking.