I recently came across the male_rape and female_rape tags, and I assumed that they applied to rape of male and rape of females, respectively. However, after looking through them, I found that there was a mixture of both those interpretations and the interpretations of rape by males and rape by females, respectively.
To resolve this ambiguity of interpretations, I think it could be a good idea to alias both to just rape, and then to create a group of tags in the line of <gender>_raping_<gender>, with appropriate <gender>_raping and <gender>_raped tags to go along with them.
Any thoughts?