Here are comments on the format 06 draft.
Are there going to be more revisions of the draft?
If so, a note should be added to section 4.2 about interoperability
with PGP 2.6.x:
PGP 2.6.x rejects signature packets of length type 0 as invalid and
does not recognize public key packets of that type. The OpenPGP draft
just says that old format packets must be used with PGP 2.6.x, but
does not mention this restriction.
BTW, why do clear-signed messages have a "Hash:" header? The hash
algorithm is given in the signature packet.