The tag implication #51749 male_penetrating_anthro -> male_on_anthro is pending approval.

Reason: All the _penetrating_ tags should really implicate the _on_ tags

These mixed-form penetrating tags should really be aliased to their *_on_* counterparts. male_penetrating_anthro can be searched for using male_on_anthro male_penetrating anthro_penetrated, without needing an explosive number of <gender>_penetrating_<form> and <form>_penetrating_<gender> tags and associated implications. The admins have also been reluctant to validate more x_verbing_y tags because of the number of combinations.