Comment lines may appear anywhere in the configuration file. A comment is introduced with an exclamation point (!) in column one. Liberal use of comments to explain what is going on is strongly encouraged. The following imta.cnf file fragment displays the use of comment lines.
! Part I: Rewrite rules ! ims-ms.my_server.siroe.com $E$U@ims-ms-daemon ! ! Part II: Channel definitions
Distinguishing between blank lines and comment lines is important. Blank lines play an important role in delimiting sections of the configuration file. Comment lines are ignored by the configuration file reading routines—they are literally “not there” as far as the routines are concerned and do not count as blank lines.