BODY_SIZE is <year:day:size>. Size is formerly arbitrary, now it is cubic centimeters I think. I used weight <-> water <-> volume for most of the animals, since volumes are harder to find.
I had noticed while doing some changes for a creature of mine in a copy of the newly-posted dwarf raws that adult dwarf size is now 6000
0.
ATTACK_CONTACT_PERC says what size to use for the body part in the attack calculations, as a percentage of the part's total size. It's all sort of iffy since everything is blobby (ie sizes are used in 1/2/3 dimensional calcs), so I either use 100 for things like punches/kicks and 1-10 for things like toothy bites.
ATTACK_PENETRATION_PERC says how deep the attack can penetrate versus body part size in the same way.
Part of me wonders whether those tags allow higher percentages than 100 for extra-vicious attacks... but since relative sizes can be adjusted, such an option wouldn't make much sense for creatures anyway. Maybe for weapons, depending on how they work now.
It'd take a bit of time to distill it down, so for now I'll just throw a raw at you. It's still preliminary in a few ways, mostly just the fingernails, but I haven't done my last-minute check on it before the release.
A belated "Whoa!" here, though I already dove into the raw.
The one I'm currently not entirely sure about is APP_MOD_IMPORTANCE. If the earlier screenshots hold, it doesn't
seem to govern where in the in-game description that trait appears. If it isn't, maybe it's to determine how important the dwarves themselves consider that trait?