Comment

A comment is a command line or part of a command line in DCL that is ignored by the CLI. Comments are marked with an exclamation point (!).

Example

Consider the following command procedure, TEST.COM:

$ show time !This comment is ignored
$! This entire line is ignored as well
 

Here is the result of running it:

$ @test
  19-DEC-2018 11:19:38
 

Use

The most important and obvious way to use comments is documenting a command procedure:

$  !  Copyright (c) 1987 Digital Equipment Corporation.  All rights reserved.
$  !
$  !  MONITOR.COM  (Generate MONITOR recording file)
$  !
$  !  This command file is to be placed in a cluster-accessible
$  !  directory called SYS$MONITOR. At system startup time, for each
$  !  node, it creates in SYS$MONITOR a MONITOR recording file, which
$  !  is updated throughout the life of the boot. It also creates in
$  !  MON$ARCHIVE, a summary file from the recording file of the
$  !  previous boot, along with a copy of that recording file.
$  !  Logical name definitions for both cluster-accessible directories,
$  !  SYS$MONITOR and MON$ARCHIVE, must be included in SYSTARTUP.COM.
$  !
 

Another use of comments is disabling a command line that is not needed now but may be needed in the future:

$! Uncomment the following command to start the OpenVMS Management
$! Station server application.
$!
$!$ @SYS$STARTUP:TNT$STARTUP