Revocation list are used to check the validity of a digital ID offline.
Offline means that your application (e.g. your browser) is consulting
the latest certificate revocation list (CRL), which it has stored locally
on your harddisk, if its needs to verify the validity of a certificate.
CRLs are issued on a regular basis. To improve your system's security
you should also download and install the newly issued CRLs periodically.
