Sankaku Channel/

System said:
A lot of poorly conceived, vague or entirely subjective tags have been aliased into "useless_tags", where they will be cleaned up where possible and removed (the reasons are recorded in the alias rather than a wiki).

Why was “pleasure_face” aliased into it? I’ve always used it as a less-extreme “ahegao”, and I recall it being a decent tag. Not sure why it was considered “vague”. Is naughty_face also vague?

And I’m about to go to sleep so I don’t have much time to research, but these three tags look like they should be aliased into something else:
oral_penetration
oral_insertion
mouth_penetration