---+ HeaderProposalTwo
The header is used in both requests and responses.
So it must be flexible to accomodate the different software and paths involved.
Based on the HeaderProposalOne the major change is that for a single destination accesspoint there will never be multiple destination elements. Multiple datasources can be addressed within a single destination header element. This allows the provider software to ignore the filtering of the destination elements to detect only destinations meant for itself.
The software/version element was integrated as an attribute into the source element, because for each source on the way there might have been different software acting on the document.
---+++++ Request Header Example
---+++++ Response Header Example