Recently, my DS (15) has been talking a lot in an online group chat filled with people that he knows in real life, but 2 or 3 people that he doesn't. I decided to look at this chat, just to make sure he is being safe, and noticed something odd. There is a lot of mentions of this specific abbreviation: 21CB. No matter how much I look on the Internet, I can't seem to find a straight answer. Another phrase that was frequently used was "Couch curry" which I don't understand, either.
I've asked him about it and he just seems to avoid the question. Is this code for drugs or something sinister? Please help!