Based on my answer here, I would like to propose the implementation of a tag black list.
The black list should contain a list of tags that should NOT be used on the site and disallow people with tagging rights to use these tags, for example the case of using the belongs-on tags.
I would also suggest increasing the tagging rep limit however this was previously covered here.
As mentioned by Chris the list should only be accessible by moderators and possibly 10K moderators to ensure that the list is kept tidy. However for 10k moderators a voting process will be put in place to add a tag to the blacklist.
The list should also be updated when moderators merge tags. The removed tag should automatically be added to the black list.
Blacklisted tags can appear as strikethroughs on the tag field when editing or adding a new question, and be validated accordingly.
Additional Nice to Have
When tags are edited they should not bump questions, as this ends up creating a lot of noise on the homepage.