About UEL/VUEL for shell element

Hello, I'm trying to program a quadrilateral classical Mindlin flat shell element (full integration for membrane, bending and selective reduced integration for transverse shear).

Now, the situation is: 
for pure tension test, it works well (because only the membrane part works),
for pure bending test, it gives very bad result compared with S4R, and I find that's because the incremental rotations at each step are different.

I have a vague recollection that the incremental rotations passed into vuel from abaqus are expressed in nodal local coordinates. But I didn't find any information from the manual or instructions about user shell element.

1. Have anyone succeed program a shell element in vuel/uel? Any special procedures for rotation dofs?
2. The rotations are in global or local coordinates?

all comments are welcome.