REM

Remark statement that can be placed in system files such as the autoexec.bat or config.sys by placing "REM" (followed by a space) in front of a line. Doing this would remark the line and prevent it from executing the next time your batch file is ran.

Alternatively, you can also place two colons (::) in front of a line to remark a line in a batch file. With two colons the line will not be displayed regardless if echo off is in the batch file.

Also see: Comment, Nonexecutable statement, Programming definitions