Tag implications: *_ponytail -> ponytail.

side ponytail
high ponytail
short ponytail

...should probably all imply ponytail.

I wouldn't do it

they ARE ponytails, but I often search specifically for normal ponytail or side_ponytail

this one would only complicate searching

I think I'd prefer side_ponytail and high_ponytail to be separate, since they have a distinct look. short_ponytail could refer to a any of them (for instance, a short side ponytail like kyon_no_imouto's) and so shouldn't be implicated if the other two aren't.

yeah, please don't do it

I don't want to have to add

-side_ponytail
-high_ponytail
-short_ponytail

everytime I want to search for a normal ponytail

it wasn't such a bad idea, but this one will make things harder