Cracking the code of teens' IM slang CNET News.com: "For parents of teens, three-letter acronyms like PAW, MOS and CD9 might be more disturbing than the old four-letter words.
Call it a sign of the times. Most teens are like a duck to water when it comes to instant messaging and mobile text messaging, where acronyms and slang can be used to keep outsiders guessing. But for parents who likely aren't as comfortable with IM slang: PAW means 'parents are watching'; MOS is 'mom over shoulder'; and CD9 means 'Code 9' for when parents are around. Research shows that one in four kids use such lingo daily to warn their chat friends of prying eyes."