This standard specifies: 1.1 A system for classifying power take-off (PTO) drive shafts; 1.2 The requirements for PTO yoke bosses; 1.3 The PTO drive shaft sizes; 1.4 The positioning of the power input connection (PIC) for PTO-driven implements; 1.5 The clearance zones; It applies to PTO drive shafts required for the connection of agricultural machines and implements to agricultural tractors. The purpose of this Gulf standard is to assist the designer in choosing adequate principles for the positioning of power input connections to provide the best possible matching conditions between different types of agricultural tractors and implements to ensure interchangeability.