A CRL-retrieval reply is an RFC 1421 CRL-type privacy-enhanced message containing retrieved CRLs, their certification paths to the RFC 1422 Internet certification authority, and possibly other certificates.
Since the reply is an ordinary privacy-enhanced message, the retrieved CRLs can be inserted into the requestor's database during normal privacy-enhanced mail processing. The requestor can forward the reply to other requestors to disseminate the CRLs.
Example:
To: requestor@host.domain From: cert-service@ca.domain -----BEGIN PRIVACY-ENHANCED MESSAGE----- Proc-Type: 4,CRL CRL: <issuer's latest CRL> Originator-Certificate: <issuer's certificate> CRL: <other issuer's latest CRL> Originator-Certificate: <other issuer's certificate> -----END PRIVACY-ENHANCED MESSAGE-----