Rating not counted as tag in search?

So I'm wanting to look through a certain rating, but cut out a few things to refine my search... but apparently, you can't "Just exclude tags"... Which confuses me, to be honest. I mean, I swear I've done this before, and it was fine with it. I mean, you can just search through rating:s, right? So why can't you search rating:s -panties or something similar?

rating, score, id, post date, poster, size, and dimensions are effectively metatags, they're stored separately in the datbase and it's ridiculously intensive on the database to search a metatag and an excluded tag.

See also forum #72856

RaisingK said:
See also forum #72856

Ah, thanks. Didn't know the terminology so I must have glanced over that.