We have had some discussion on OpenPGP of a flag, perhaps in the literal
packet, which would indicate that messages are in this form. Perhaps a
future version will have a clean way of doing this.
This would also be nice for super-encrypting messages, for something like
IDEA(CAST(plaintext))
Perhaps have an 'n' for nested mode in Literal packets that tells clients to
treat the contained data as another PGP data structure.
Ian.