This read-only counter tracks the number of SMDS PDUs discarded due to a mismatched group or individual address, when address verification is enabled. Admins monitor this to see how much traffic is being rejected by the address-verification check, which could indicate either legitimate security filtering or an addressing misconfiguration. For example, a high discard count here on a circuit that should only be receiving properly addressed traffic would prompt the admin to check whether the remote end's addressing configuration matches what's expected locally.