So @falco - sorry I think I could have expressed this issue better if I had understood it better (as I think I do now thanks to your help so far…)
The issue is that even if a tag is not attached to any topic, it still EXISTS (and is selectable by a poster). So it needs to be deleted if we don’t want anyone to use that tag.
However, if a tag is not attached to any topic, it no longer appears in the /tags page so cannot be accessed to delete it.
Does that make more sense (as an explanation of the issue…)?