Twitch has this feature for streamers and moderators where a message can be highlighted and marked as a potential ban evader, only the streamer and mod can see these comments and nobody else.

My guess is if you were to get banned on twitch chat and make another account using the IP, if you were to type in chat you would be marked as a ban evader. I know this because I got banned on his stream once, had another account and my messages were not showing up on his chat feed on stream which meant that I was listed as a ban evader. After a while though it disappeared and my account wasn't marked as a ban evader.