How to invert the search for custom tags?

I’d like to search for tracks which don’t contain a certain tag. Is this possible?

In the quick filter (at the top of the track browser) that’s not possible. But you can make a smartlist with a rule for that

Thanks for the clarification! Many times smartlists are not feasible because the reason for the search is rather temporary. It would be helpful to have that but the search syntax could be tricky. The obvious choices - and ! are allowed as first character of a tag so Lexicon would need to take care of that by making obvious what’s going on.

Exclamation mark is already special for tag search, it turns it into an AND search. So

!Techno, VocalsTechno AND Vocals

But maybe ~ makes sense. So Techno, ~VocalsTechno but not Vocals

Ok ~ sounds also good. But ! for AND in front of the search is a bit counter intuitive… I wasn’t even aware of that option and when I looked up the documentation I saw that negation with ! is in fact used for BPM search. Maybe this is an opportunity to streamline the syntax?