It is sometimes too difficult to remember my options in Link/Tag Sets

(Bug, Investigate , Priority: Medium, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Tag Sets, User Interface
Summary: When there are more than a modest number of Tags/Links to choose from, the Manifest UI on its own becomes hard to use -- the solution space is too large, and it's hard to remember the name of what I'm looking for.
Pointed out by Anna, although I'd noticed the problem myself before.
The solution probably involves some kinds of "show all" mechanism, but we'll need to puzzle out the right UX for that.