This GitHub repository hold DFDL schemas that model HL7 v2.7 healthcare messages.
The schemas provide DFDL-annotated objects that model HL7 segments, fields and data types, and a generic HL7 message that consists of an MSH segment followed by any number of HL7 segments or user-defined Z segments.
This is a public repository that allows anybody to view and download the content. If you would like to contribute to this repository, email the address on the organisation home page.
Data Format Description Language (DFDL, often pronounced daff-o-dil), published as an Open Grid Forum Proposed Recommendation in January 2011, is a modeling language for describing general text and binary data in a standard way. A DFDL model or schema allows any text or binary data to be read (or "parsed") from its native format and to be presented as an instance of an information set. The same DFDL schema also allows data to be taken from an instance of an information set and written out (or "serialized") to its native format.
If you are new to DFDL a good place to start is the DFDL page on IBM developerWorks. This contains links to DFDL implementations, tutorials and videos.