In a batch file
REM signifies a comment or REMARK
adding :: at the start of a line has a similar effect
:: First comment
REM Second comment
Although you can use rem without a comment to add vertical spacing to a batch file, you can also use blank lines. The blank lines are ignored when processing the batch program.
The double-colon is not documented as a comment command, it is a special case of a CALL label that acts like a comment. The pro&qt;&qt;s and cons of each method are listed below.
There are problems using a :: comment within an IF or FOR code bracket
FOR /L &qt;&qt;i IN (1,1,10) Do (
Echo before comment
:: Some comment
Echo after comment
The above will return the error :: was unexpected at this time.
In the script below the DIR command will set an &qt;errorlevel&qt;=2 if the file is not found, but the REM command is then executed successfully and resets &qt;errorlevel&qt;=0
If you use :: for the comment the errorlevel stays at 2.
REM some comment
The problem above was fixed* in Win XP and later service packs of NT 4.
Finally in Windows 2000 and XP a comment like
REM &qt;~ will be interpreted giving the error:
The following usage of the path operator in batch-parameter substitution is invalid: &qt;~
The bottom line on this is that you must test your comments to be sure they will be ignored as you expect.
Within a registry file comments can be preceded by "; "
; Turn the NUMLOCK on at login
There is no valid comment character for FTP but you can cheat by escaping to the shell and running REM
!REM This is a remark
ftp> !REM This is a remark
* The errorlevels set by DIR are different under Windows NT 4 and XP