It would be very helpful if there was a category search similar to the advanced genre search, so that it would be possible to include several categories and exclude others.

Uhh you can already search multiple categories at the same time. And I believe you can exclude categories by using "-" in front of a category (not sure since I haven't tested it yet myself).

Like tart said you can do those things.

Quote from above the box you put where you put the tags

Categories/Tags [color=blue](one per line)[/color] See the tag dictionary

If you want to search multiple tags. Ex. , Popular female lead, Friends Become Lovers, but want to exclude Age gap, Childhood friend/s

In the box you would put

Popular female lead
Friends Become lovers
-Age gap
-childhood friend/s

Each would take it's own line.

Yes yes, I know I make longwinded comments, but that's just me >.<
I should proof read my comments more, but I won't...
So keep in mind I'm filled with typos

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