Ex. 6/6: Rating

    +------------+
    | comment    |
    | done-tag   | -> public
    | rate-tag-A |
    | PGP-sig    |
    +------------+

    +------------+
    | comment    |
    | paym-tag-A | -> public
    | rate-tag-D |
    | PGP-sig    |
    +------------+

    (same for B)

rate-tag: urn:trade:rate:devel@a.net:1.7:2006-04-13:1