Multiple PartyIDs in From and To

[Pim van der Eijk <pvde@sonnenglanz.net>]

Hi,

Sections 5.2.2.3 and 5.2.2.5 of EBMS3CORE state that there can be more than one PartyId in From and To elements and requires them to identify the same organization:

eb:Messaging/eb:UserMessage/eb:PartyInfo/eb:From/eb:PartyId: The REQUIRED PartyId element occurs one or more times. If it occurs multiple times, each instance MUST identify the same organization.

Appendix D.3.1 states that these values are taken from PMode.Initiator/Responder.Party.  

A user message initiating an MEP instance under this P-Mode must have its eb:Messaging/eb:UserMessage/eb:PartyInfo/eb:From element contain the same PartyId elements as the PartyId elements defined in this parameter.

One user thought this feature could be used to allow a receiving MSH to identify parties using multiple party ID types (e.g. GS1 GLN or D-U-N-S or whatever),  leaving a choice of which type to use to the sender without having to define a separate PMode for each case.  Another use case could be for hubs that handle messages on behalf of multiple organizations (e.g. branches of a single companies,  or different companies using a service provider) with diferent identifiers.   If we could just select one PartyId from the ones in the PMode,  we could have a single PMode for all organizations using the hub.  But it looks as if D.3.1. if requiring the same number of PartyIds have to be present, with the same content,  in the PMode definition and in the From/To headers.    And therefore,  it would be an error for an MSH to select just one PartyID from the ones defined in the PMode.  What do you think?

Pim