I’ve asked for something like this before, but I’m going to ask again…
At present, there are several ways an item can acquire a tag:
- By manually adding a tag to the item
- By inheriting tags that are parent tags of manually added tags
- By adding tags to the containing group of the item when ‘Inherit Tags of Groups’ is enabled for a database.
I call the first way (manual) a HARD tag, and the other two ways a SOFT tag.
This is all good, and I use all three methods when organizing my data.
BUT, when DT shows the tags for an item (in the tags bar at the bottom of the item, or in the item properties pane), it doesnt show which are soft and which are hard tags. This makes tag housekeeping messy. For example, an item can sometimes have the same tag as both hard and soft (often by mistake), and this is impossible to discover except by experimentally removing and adding a tag to see what happens. When doing major cleanups of tags (as happens when a database grows), this gets very time-consuming, even with that automation features of DT.
Ideally, it would be great if DT offered two new features to help with this:
– Show soft tags in a different color in the tags list (e.g. pale yellow background compared to the pale blue used for all tags at the moment).
– Add a new search prefix “stag:”, that is identical to the current “tag:” prefix but only matches soft tags, so that you can make searches that find soft, hard or all tags with various combinations of these prefixes (e.g. any and not soft == hard).
Of course, this is a “power user” type of request, but isnt that kinda what DT is about? 
(P.S. I think this would also make tag editing easier to understand. I’m sure many people get very confused when they manually delete a soft tag from the tag list only to have it re-appear moments later. Making it clear which tags are soft would to a long way to clearing this up imho.)