This part of ISO 17972 defines an exchange format for colour and process control data (and the associated metadata necessary for its proper interpretation) in electronic form. It is the base document for describing the use of CxF3 for data exchange. Where required, this part of ISO 17972 also defines additional requirements for a valid CxF/X file. Using XML, all CxF3 and CxF/X documents also support the exchange of data outside of the graphic arts workflow and can support future standards with an extensible architecture using standard XML Names and Metadata tags which can be used with standard XML tools and pass XML validation. Additional parts of ISO 17972 will use custom resources in conjunction with CxF3 to define the required and optional data for a particular workflow.