The syntax of the list is a sequence, separated by newlines or ;, of check or no-check actions, along with a CIDR block or all. When an CIDR IP range has the setting no-check, no hostname verification will be done; if it has the setting check, hostname verification will be performed. Hostname verification is performed on all addresses by default. Only IPv4 and IPv6 addresses are recognized by the filter, meaning that hostname verification will still take place for other addresses. The filter will apply the first rule it finds in the sequence.