This is meant to agglomerate tags that need (occasional or regular) cleanup. That is tags that mean multiple unrelated things and need to be separated into more specific tags. Please follow the examples below and discuss specific needs in comments or separate questions, as necessary.
Conversely, some subjects are scattered over several tags and there it might make sense to merge some tags and to create synonyms. Proposals for such can also be added as answers.
As of August 8, 2017, the length limit for tags went from 25 characters to 35 characters. So now is a great time to allow inconveniently compressed tag names to stretch out a bit...
PS: If you want to cleanup these tags, please keep your rate down to a few posts per day so that your edits don't clutter the main page. Also note that merges can be done by moderators in one go without bumping questions. Thus, it is usually better not to carry out non-minimal merges manually (where non-minimally could mean more than three to five).