Comment (-COMMENT)
Use the Comment adapter command (-COMMENT) to specify the comment that appears in the encrypted or signed message's header. This adapter command corresponds to the --comment GnuPG command option.
-COMMENT " comment "
For example:
-COMMENT " Message signed with GnuPG "
When the -COMMENT adapter command is not present; the comment is omitted from the generated message.
When the comment value contains no white spaces, quotes can be omitted. However, note that on UNIX™ systems, the adapter does not support comments with white spaces. Replace the white spaces with other characters, for example, the underscore character '_', before passing it to the adapter.