<Snipped quote by Cerberov>
Gavelkind destroys kingdoms! Definitely the bane of my existence in Crusader Kings 2.
Though Uterine sounds a lot like absolute cognatic succession to me (females inherit on the same grounds as men). Sort of.
Basically:
When a king dies during cognatic succession, the right passes to male children, then brothers, then any daughters or sisters. Uterine succession is more similar to agnatic: if a king dies, it goes through siblings, then to children, favoring the closest female ancestry. If a woman inherits, there'd be pressure to pass her claim off to a male heir, but she still has a legitimate claim. Cousins aren't even counted until the main line has been wiped out, and in-laws aren't even in the line of succession.
I got it completely wrong. If a king dies, the succession would be his sister's child, then his children, then a brother, then his sister.
Also, good job, Vahir. Considering how complex our character sheets are getting, a wiki's the next logical step.