Suggested Requirements for Multi-part Multi-Structured 822 Encoding

[David Robinson <DRB@xxxxxxxxxxxxxxx>]

As a way of evaluating the alternatives, I would like to suggest that the
following are reasonable requirements for a multi-part multi-structured
RFC-822 mail encoding mechanism:

    o  Multi-part and multi-structured (nothing goes without saying)
    o  Nestable.
    o  Rigorously machine-parsable.
    o  Easily parsable by human with editor.

MULTI-PART and MULTI-STRUCTURED.  A message must be able to contain one
or more parts and those parts must able to be of different structures/
types/contents.

NESTABLE.  One of the structure/type/content must be able to be an entire
mail message (which may itself contain parts).  There should be no
theoretical or practical limit to the number of levels of "nesting".

RIGOROUSLY MACHINE-PARSABLE.  It must be possible to write programs to
handle composing and decomposing multi-part multi-structured mail
messages.  These programs must not be "fooled" by any user-generated
message contents.  (Eventually, most users may have these programs.)

EASILY PARSABLE BY HUMAN WITH EDITOR.  A human mail recipient should be
able to compose and decompose a multi-part multi-structured mail message
with a simple editor.  (In the beginning few users will have the
composition and decomposition programs.)