Comments are used in the policy script to document how a particular test, action, or control statement contributes to a filter. For each line of commented text, use the “#” character followed by a single space to denote information the Sieve interpreter should ignore.

Note Comments should not be placed within multi-line strings.
Generic Example:
# Comments
# More comments
if test { # This is a valid comment!
Policy Script Example:
# This filter scans all message headers for the words "Buy Now!"
# If this string is found, PureMessage rejects the message
# and the filter stops evaluating the message for spam.
if header :contains "Buy Now!" {