I used a certain tag on indexed files related to a recent project. The current phase of the project has ended, and I want to untag the items , but I don’t want to lose track of the fact that those items had this tag, in case I need to find the items again in the future. How can I retain the information somehow, but still untag the items in question?
If there were such a thing as “active” and “inactive” tags in DEVONthink, or perhaps “hidden” tags, that might provide the solution  – then I could mark that tag inactive or hidden and have it disappear from item properties, yet still make it possible to reactive/unhide that tag in the future. Since there isn’t, I wonder if anyone has an alternative strategy they could share?
Special wrinkle: these are indexed files (specifically PDFs of academic articles stored in Zotero), so it won’t work to (say) create a new database, copy the files to that, archive that database, and then untag the files in the active database. (It won’t work because it would be impossible to restore the files into the active database afterwards.)
 Why untag them? I have a large hierarchy of tags, and the way the DEVONthink UI works means that the tags are displayed along with their parents, which leads to cluttered views. Removing these “inactive” tags would help me.
 This is not necessarily a feature request; I’m only using this as an example to try to further clarify the question.