The document presents a framework to assist the writers of certificate policies or certification practice statements forcertification authorities and public key infrastructures. http://www.ietf.org/rfc/rfc2527.txt
The PKIX specification profiles the format and semantics of fields in X.509 V3 certificates containing Key Exchange Algorithm (KEA) keys, a classified algorithm for exchanging keys. http://www.ietf.org/rfc/rfc2528.txt