Gimbal parameter list

Where can I find a list of parameters that the autopilot can send to a Gimbal?

I am listenning to the comunication between an autopilot and a mavlink gimbal, and I see messages like Param Set for:
GMB_SYSID, GMB_POS_HOLD, GMB_MAX_TORQUE, GMB_SND_TORQUE

Is there documnentation where I can see a list of the parameters?

Thanks!