The following list describes additional rule set features.
Numbered rule sets are also named, but the rule sets can still be accessed by their numbers.
The H header configuration file command allows for a default rule set to be specified for header checks. This rule set is called only if the individual header has not been assigned its own rule set.
Comments in rule sets (that is, text within parentheses) are not removed if the configuration file version is nine or greater. For example, the following rule matches the input token (1), but does not match the input token.
R$+ (1) $@ 1
sendmail accepts the SMTP RSET command even when it rejects commands because of TCP wrappers or the check_relay rule set.
You receive a warning if you set the –OperatorChars option multiple times. Also, do not set –OperatorChars after the rule sets are defined.
The name of the rule set, as well as its lines, are ignored if an invalid rule set is declared. The rule set lines are not added to S0.