The list of deformations is at the beginning of ModelManager class.

And explanations are given in this thread about version 6.0, here and here (for ball-arm joints). Then Sweet Home 3D version 7.0 brought new prefixes to specify the moves of shapes relative to other moving shapes.

Actually, prefixes used for mannequin deformation are ball-arm joints, and since version 7.0, they could be replace by sub transformations. Then, you could use how many numbered ball-arm joints as you wish for more than one mannequin in a OBJ file. Nice exercice which requires some patience... If you succeed, please share your result [:)]