It's a retarded rule and that's a hill worth dying on, but it's also about as synonymous with vtubing as not posting pastlife shit is. If you fuck up and break this rule literally everyone knows - especially while spending money to do so - you deserve the public execution.This is such a bizarre thing to me. Maybe I have just been in the scene too long, but the "don't bring up other streamers unprompted or bring me up unprompted" is an extremely common rule in the streaming world where it is pretty safe to assume everyone has it as a rule for chat.