CRL (Certificate Revocation List)
Certificate Revocation List (CRL) is one of two common methods when using a public key infrastructure for maintaining access to servers in a network. CRL stands for Certificate Revocation List. It is a list of certificates (or more specifically, a list of serial numbers for certificates) that have been revoked, and therefore entities presenting those certificates should no longer be trusted.
The other method, which has superseded CRL in some cases, is Online Certificate Status Protocol (OCSP).