- "Replacing with more useful ones" IMHO makes not much sense, with 13 questions altogether. That would mean at least 5 tags with probably less than 3-4 questions each.
- Seeing the tags in combinations, they seem to make sense. Browsing e.g. the
gmail tag and see a question additionally tagged
filter, the meaning is pretty clear. Also initiating a search for
[gmail] [filter] would yield the corresponding result(s).
- Most questions could probably be re-tagged (or have the
filter tag simply removed).
All depends on how you look at tags, and I'm a bit torn between two thoughts: If you think about tags as "filters" (sic!), I'd say we leave is as-is. If, however, each tag should have a significant and specific meaning, there's no way for a
filter tag to survive: As shown by the existing usage (and I wonder there's not also a question on screen-/display-filters), it would be much too broad – and stand-alone tags for each of the different meanings would turn out in tags with 1-4 questions each, which wouldn't be very useful either.
I'd rather say declaring
filter a "generic tag", as it is currently used, and give it a corresponding description, e.g.:
for questions involving a filtering process of any kind. This is to be used in conjunction with a descriptive tag giving it a real meaning, don't use it stand-alone.
It's tag-wiki could give some more elaborate examples then of how to use it and how not to use it.