struct PK_FACE_split_at_param_o_s { int o_t_version; --- version number of option structure }; typedef struct PK_FACE_split_at_param_o_s PK_FACE_split_at_param_o_t; This options structure will hold optional controls for PK_FACE_split_at_param. Description of fields: o_t_version version number of option structure.