"Primary Business Document"

[Dan Weinreb <dlw@exceloncorp.com>]

In the BPSS spec (version 1.01, 11 May 2001, page 21, line 798, sec
6.4.1.4) it says that a "Each Document Envelope carries one primary
Business Document"; shortly thereafter it says that "A Document
Envelope can optionally have one or more attachments".

I haven't found any spec that spells out the mapping between the
concepts and terminology of BPSS with those of MS.  In this case, I
would guess, just because it seems natural, that BPSS's "primary
Business Document" would be the equivalent of MS's "the contents of
the first Payload Container", and the BPSS "attachments" would
correspond to "the contents of the second and subsequent Payload
Containers".  But maybe this guess is wrong, and it does seem that it
ought to be specified somewhere or other.

In fact, it would not hurt to spell out the fact, if I'm not mistaken,
that every BPSS "DocumentEnvelope" is implemented by one ebMS
"Message", whereas some ebMS "messages" do not correspond to any BPSS
"DocumentEnvelope" (including but not limited to those with no payload
components).