This doc defines a common reason doc signing KeyPurposeId for inclusion in the Extended Key Usage (EKU) extension of X.509 public essential certificates. Tadahiko Ito, Tomofumi Okubo, Sean Turner, 2022-03-31, RFC5280 specifies many prolonged crucial reason identifiers (KeyPurposeIds) for X.509 certificates. CMP is used to enroll and further more control the lifecycle of X.509 certificates.