REM--Notes

Using the ECHO command to display comments

The REM command does not display comments on the screen. You must use the   
ECHO ON command in your batch or CONFIG.SYS file in order to display
comments on the screen.

Restrictions on characters in batch-file comments

You cannot use a redirection character (> or <) or pipe (|) in a batch-file
comment.

Using REM to add vertical spacing

Although you can use REM without a comment to add vertical spacing to a
batch file, you can also use blank lines. MS-DOS ignores the blank lines
when processing the batch program.