(Split off from my answer to Merging / synonimising tags should warn of tag wiki loss...)
The whole interface for this feature is terrible! It has almost no useful information for the poor moderator.
"Source"? "Target"? No matter so many tag merge requests have come out backwards that I've seen. The poor moderator has to take a stab in the dark. Why not call one "Synonym" and the other something like "Main tag" or whatever?
When you enter valid tags it should tell you useful stuff about each tag:
- Preview of wiki and/or excerpt
- Creation date
- Whether this tag already has synonyms, how many, what they are
- How many questions each tag is already used on
- How recently each tag was applied to a question
- How recently each tag had its tag wiki and/or excerpt edited
- Maybe the users who created them, use them the most, used them most recently
- If there were votes for adding the synonym (in either direction), show total plus number of each up and down votes
- Would an option to revert/undo when a tag merge was applied "backwards" make sense and fit into the interface?
- Are the old tag wikis for the tags which have now become mere synonyms still stored in the database somewhere? Could we add a way to import/reinstate a tag wiki from a synonym to the new main tag? Could it work even for synonyms made some time ago?
OK some of that is not strictly necessary but might help the mod and won't be hard to implement. But some of it I think is really essential.