This standard deals with: — essential dimensions to ensure mechanical interchangeability; — recommended dimensions; — wiring connections to contacts of plug and socket; — marking of contacts of plug and socket; of three-conductor and four-conductor high-voltage cable plug and socket connections for medical X-ray equipment. Notes 1. — Ratings of maximum potential difference and electric current are not dealt with in this standard because the behaviour of a high-voltage cable plug and socket connection depends on the materials of the cable termination plug assembly and the receptacle socket assembly, and upon environmental factors. 2. — This standard does not include details or particulars of means for preventing removal of the ring nut (see Sub-clause 2.2) or of the cable termination plug assembly without the use of a tool. 3. — In cases where high-voltage connections of a type not complying with this standard are used, the X-ray equipment shall comply with the appropriate IEC standards.