Revocation lists identify digital certificates that have been revoked by the certificate authority. The DeltaV software enables you to import revocation lists to automatically untrust revoked certificates. Perform this procedure when you receive a revocation list from the certificate authority. Put the list in the DeltaV\DVData\Import-Export or to another location where it is available to the ProfessionalPlus workstation. Revocation lists have a .crl extension.