The OCSP (Online Certificate Status protocol) is an Internet protocol used to check in real time the revocation status (valid, revoked, suspended, expired or unknown) of a certificate.
InfoCamere OCSP services for qualified certificates are available at the URL http://ocsp.sc.ca.infocamere.it
Certificate Revocation Lists (CRLs) contain information on revoked certificates. CRLs are cumulative and contain information on all currently revoked certificates. Certificates that are declared invalid remain in the CRL at least until they expire.