I have recently found out that some fetish tags, like rape for example do not show results (despite some games containing the tag) when searched for, while others, like vore do. Despite being equally offputting.

After this, I decided to try out a few other controversial tags to see if there are any more interesting search censors... here are the results:

Cub (has results, 2 of them furry) - if you didn't know, cub is the word used to describe a furry character that is made to look underage
Loli (no results)

Scat (has results)

I can't really think of any more off the top of my head, but yeah... the fact that the censorship isn't consistent is what worries me...