IEC CA 01:2017 provides a framework and sets out the basic rules for the structure and operation of the IEC CA Systems. This harmonized set of rules ensures that the Systems operate in a consistent and transparent manner while allowing flexibility for the individual Systems to serve the needs of their respective customers, providing a mechanism for easier collaboration between the Systems. This harmonization also provides an opportunity to promote the use of existing, and proven, best practices across the IEC CA Systems.