@Xabid: Honestly, I say let's just start using a...

Xabid
2010-03-11T11:40:05-05:00

Honestly, I say let's just start using a small_breasts tag. It doesn't do any harm; it's not a subjective tag, and it's at least trying to make a useful distinction. Worst case people ignore it... tags are fairly cheap.

I mean, yeah, there's a point where there's too much and it's just annoying clutter (I'm thinking of all those horrible cum_on_xyz tags here), but I don't think this is anywhere near that line.

Negative tags, as noted, don't really work -- with a positive search, inconsistent tagging means you miss some things, but still get overall useful results. With a negative search, it can make your search totally useless (because your results will be cluttered with stuff where people forgot to add tags that should have excluded those images.)

Negative searches also fail to work completely on any image with multiple pairs of breasts of differing sizes, which is pretty common.

And it makes some things that should be extremely easy straightforward searches ("character_x with small_breasts" or "small_breasts and red_hair") into convoluted monstrosities that will be full of bad results for the above reasons.