Sendmail, 3rd Edition

Chapter 18

Section 18.2.1	Rules (the R lines) can no longer exist outside of rule sets (the S line) without producing an error (V8.10 and later).
Section 18.2.1	If the configuration file lacks a correct version number (the V line), sendmail will complain (V8.9 and later).
Section 18.2.2	Prior to V8.10, RFC2822-style comments were removed from all rules.
Section 18.3	An error will print if the OperatorChars option is declared after any rule (V8.10 and later).
Section 18.6	The $# operator can now appear in the LHS of a rule (V8.9 and later).