This site is really useful and includes a list of lingo and their abbreviations that children may use. http://parentinfo.org/article/online-teen-speak-updated
Here’s some popular teen chat acronyms:
•ASL – age, sex, location (could mean your child is using an anonymous chat room)
•CD9 – Code 9 (meaning parents are around)
•GNOC – get naked on camera
•KPC – keep parents clueless
•IRL – in real life. See also: MIRL – meeting in real life LMIRL – let’s meet in real life (fine if it’s their friends)
•IWSN – I want sex now
•MOOS – member of the opposite sex
•P911/P999 – parent alert
•PAW – parents are watching
•POS/MOS – parents over shoulder/mum over shoulder
•RU/18 – are you over 18?
•WYRN – what’s your real name?
•Zerg – to gang up on someone
•420 – marijuana