Okay... here goes nothing :s

A month or so ago, a Forum (forum #17012) was started on the topic of breast size. There was a bit of confusion and a number of alternatives were presented. There was also a bit of a discussion that went off-topic. In an attempt to bring some consensus, I've started this new Forum topic.

Early on in the other Forum, a list of various existing tags, along with their counts, was listed as:

breasts – 39,493 posts (now 42,680)
big_breasts – 5,743 (6,661)
huge_breasts – 1,332 (1,462)
hyper_breasts – 600 (625)
small_breasts – 520 (545)
natural_breasts – 11 (41)
bouncing_breasts – 21 (25)
oversized_breasts – 22 (22)
droopy_breasts – 22 (0)
perky_breasts – 2 (0)
heavy_breasts – 1 (0)
sagging_breasts – 1 (0)
tiny_breasts – 1 (0)

However, it appears that some of these tags have already been aliased (is that a real word?) into other tags.

From Wiki, we have the following descriptions:
Breasts: This tag is used any time bare breasts appear for a female character, or where a her clothed breasts are prominently featured.
Flat_chest: No breast mound
Small_breasts: A to B cup sized breasts
Big_breasts: D to F cup sized breasts
Huge_breasts: G and up sized breasts, Hyper fetish

flat_chest: applied to female characters whose breasts are 'undeveloped or nonexistent', either because of being underage or of a species where breasts wouldn't normally exist, such as reptiles.

small_breasts: female characters with smaller than average breasts, either just naturally small or still not fully developed. This does not refer to a character whose breasts haven't started to develop or would be completely without breasts (aka, flat_chest).

big_breasts: Breasts that are above average in size, but no bigger than the female's head.

huge_breasts: unusually large, usually with notable sag and often clearly visible even when viewed from behind. Equal to or exceeds the bearer's head in size.

hyper_breasts: hyper-endowed, unrealistically large, more than can be considered artistic license.