Please sperate/remove some of the implication of the underboob tag. When I search for or tag an image for underboob, I am searching for either an image showing the undersides of breasts or breasts underneath clothing showing or implying the undersides of breasts, not for the whole boob image that just so happens to have the underside of boobs visible.
Perhaps split it up into multiple, separate tags displaying direction or implication?
Ex: implied_under_boob, topboob, partially_revealed_breasts

Here are (what is currently) at the top of the underboob lookup tag that shows what I mean:
This is under boob: https://e621.net/posts/4038479?q=Underboob
This is breasts (not underboob!):
https://e621.net/posts/4039803?q=Underboob
This is I guess underboob? (Upwards facing camera perspective showing underside, but wouldn't this be more upwards perspective tag than underboob tag?):
https://e621.net/posts/4038211?q=Underboob
This is partially_revealed_breasts:
https://e621.net/posts/4037029?q=Underboob
This is (at least I consider it to be) underboob, as the areola is not showing and it is only the underside
https://e621.net/posts/4034952?q=Underboob

Please separate/clarify/change the tag!