Elbows are allowed in intermediate (B Class) and above. Knees are allowed at all levels. Knees to the head from the clinch is only allowed A Class.
For future reference
C Class: 0-3 fights
B Class: 4-9 fights
A Class: 10+ fights
Point system is the same as boxing (10 point system); Some exceptions apply.
Sweeps are worth the most points, kicks and knees, even though blocked will still count as a point (applies to the clinch as well).
Elbows are padded in B class, some events for A class has the fighters with no gear.
Most organizations still use the template for decisive judging: ring control, aggression, effective striking.