#

A comment or remark is indicated by starting the line with the # character

   # This is a description
   # Another remark
   command
   # Another remark

Related commands:

: (a colon)

: [arguments]

Do nothing beyond expanding arguments and performing redirections. The return status is zero.

Equivalent Windows XP commands:

:: A comment/remark is indicated by 
:: starting the line with 2 colons