As we add things under the umbrella [tag:ayatana] project it's becoming too meta and doesn't really mean anything anymore.

- [tag:tips] also appears to be not useful.
- [tag:linux] isn't being used for the kernel, but more as a "I happen to be running linux" tag. That one can probably go too.

I've checked the affected questions and they all have proper tags to the subprojects, which is better anyway, so safe to remove those tags.