This part of ISO 5673 gives the forms and applications of power take-off (PTO) drive shafts for tractors and self-propelled machines used in agriculture, and specifies the dimensions for, and clearance zone around, the implement power-input connection (PIC) for a variety of attachments. Its intent is to ensure proper clearance between the PTO drive line and adjacent components on the implement and tractor when both implement and tractor have compatible power levels. It is not intended as a complete guide for drive-line design and does not, for example, contain information on preventing drive-line vibration or sizing a torque limiting device. It is not applicable to combinations of implements with tractors having high ground clearance, such as those working in standing vegetable crops or sugar cane, nor to agricultural tractors designed for low ground clearance, such as for lawn mowing or ground care, which require a low centre of gravity; neither is it applicable to implements non-symmetrical in design by necessity due to their function.