This is related to this question, about ignoring dashes in the tag search.
How about we ignore them when they're not entered, so that tags will be found with dashes or not, BUT lets allow if the user puts a dash in, to bring up just the tags with a dash.
Here's an image showing that
stl- doesn't show all the tags that start/contain that phrase, it completely ignores the dash, so the user doesn't see the other valid
I hope I explained it so you understand, I think the dash should be ignored in one direction but not the other.
NOTE: Right now it means for instance that I cannot bring up a list of all tags that start with
stl-, I have to type each letter and see what's there, like