This part of the IEC 60534 series provides a list of requirements that are normally necessary for the procurement of the majority of control valves for process systems. No attempt is made to include all possible requirements for any conceivable process. The list is arranged in a format designed to assist the specification writer with a standardized presentation of data and also to be a basis for use with data processing facilities. A detailed set of instructions is included in order to ensure that the abbreviated terms are fully understood and that consistent data entries are always made.