I propose that we be given some way to label channels with symbols, text, colours, Twitch emoticons, or whatever else that will be visible when looking at a stream's thumbnail (from the directory, our list of followed streamers, a Community, wherever). This will allow us to easily categorise streams as, say, Kappa (good for goofing off) or ResidentSleeper (chill stream). This would also be useful in lieu of a blacklist so people can know where /not/ to go (maybe a place is too offensive for someone or not offensive enough for another and they just don't want to waste their time there any more).

As an extension of this idea, some way to take notes on a channel could also be useful. Users could keep track of associated culture (mostly memes, knowing Twitch), events ("[favourite game] on Saturday" maybe wouldn't be posted elsewhere), quotes about which to mercilessly tease the streamer, why they followed this person who hasn't streamed in over a year, etc.

Sharing of tags/labels/notes may be already handled appropriately by Communities, stream descriptions, and feeds but may be worth further discussion. I'd certainly expect that should such a thing be allowed the channel owner would have control over what could be associated with them and whether or not such things could be shared at all (to prevent harassment and inappropriate/incorrect labels and notes). Additionally, some way to separate shared and personal labels/notes would be much preferred. This could lead to significant interface clutter, though (at least regarding labels, which I intend as features visible with streams' thumbnails), so I'd personally go for simplifying the system over dropping labels entirely because of an inability to integrate the social aspect effectively. Further, sharing could enhance discoverability. Iif users can affix appropriate labels and search for them too, it may become easier to find content of more particular interest such as "adventure gamer" over attempting to check every adventure game's stream list or browsing the directory just looking for such games.

To clarify, I consider this these features all part of a structure of additional information users can affix to streams to increase their ability to take part in stream communities and recognise which communities those are. The features complement each other nicely, with labels allowing users to recognise general features of a channel from outside and notes allowing users for verbose records or reminders of information specifically relevant to them. Sharing, in my mind a third matter though still relevant because it affects usage and meaning of the others, adds a social component that could be amusing or useful.

Side note: I did find an idea here about personal notes but I believe I've sufficiently expanded and scope and framing of the idea (and included another that I consider relevant besides) to merit posting this separately. Apologies if anyone finds this irritating or otherwise disagreeable.