To provide in depth analysis of how R2 EngineSendserializes an EDI document.
EngineSend is implemented as a BizTalk pipeline with EDI Assembler component in the Assemble stage.
Engine Send:
Below is a diagram of the EDISend Pipeline showing the individual component

EDISend pipeline does the following whenserializing a document

Party Resolution
Schema Discovery
Document Processing
Envelope Application
Apply Party Specific Properties (or Global)
EDI Validation
Character […]