As far as I know, there's no way to filter a category to exclude specific genres.
Like listing the "Silly Humor" category but excluding Yaoi and Shoujo titles.

On another note, it would be nice if release filtering was automatically applied to search results; whether searching in categories or doing a quick search for a specific title.

Quote from JohnHomos

As far as I know, there's no way to filter a category to exclude specific genres.
Like listing the "Silly Humor" category but excluding Yaoi and Shoujo titles.

Genre Search will do.

http://www.mangaupdates.com/series.html?category=Silly%2BHumor&exclude_genre=Shoujo_Yaoi&perpage=50

Oops, didn't notice that.

But I still think that it's better if the excluded genre's from releases are automatically excluded from search results.