Its often (rarely actually) used in chatting and online-gaming. The word can also be mix, drop and match with other short forms to suit your needs. For example, if you had a great game and now taking your leave, you may add 'gg'(good game) and maybe drop 'glhf' from it, hence making 'kkbyeggthx' (Okey bye gotta go now. Good game and thanks for the fun time). Trivia: First used and introduced by the originator, who is a weird-asian psychopath, whose initial is 'F'.