This idea just came to mind, not sure if it hast been suggested before, hard to search for, find search terms.
I am subscribed to many tags - I work on topics, changing quite often, have learned about many technologies. So I used the tagging system to remember and bookmark the view of questions about that.
But when I am in the mood of helping and checking for open questions I want to be able to reduce to a subset of tags, those which are my main profession, or/and which are currently my wishlist to think and talk about.
You understand what I am about?!
UPDATE ok, found some related questions Have "Interesting Tags" that are combinations of tags