This document specifies the rating conditions, tolerances and the method of presenting performance data of refrigerant compressors. This document is applicable to single stage compressor and two stage compressor data with or without an additional intermediate pressure inlet. The performance data of compressors used with R-744 in transcritical operation are covered in this document. The data relating to the refrigerating capacity, heating capacity and power absorbed include requirements for part load operation where applicable. Presenting performance in this way enables a comparison of different compressors.