GV_OP

GV_OP_NOP	Ignore.
GV_OP_SET	Set the internal value to the parameter value. (The constant node uses this.)
GV_OP_DROP	An atom has been dropped over the node.
GV_OP_DROP_IN_BODY	An atom has been dropped over the body of the node.
GV_OP_DROP_IN_INDOCK	An atom has been dropped in the inport area of the node.
GV_OP_DROP_IN_OUTDOCK	An atom has been dropped in the outport area of the node.