Anonymization of Examples
Anonymization (also known as de-identification) of production v3 messages/documents is probably the best way to create a set of examples for testing purposes.
Note that pseudonymization is a mechanism that produces the same "pseudonym" for the same patient (for the same "context") which is the main use case in clinical trials but also in teaching files. Pseudonymization may be advizable if scenario's involving multiple messages/documents are to be tested.
Anonymization can probably be achieved by a XML transformation (a XSLT). It is however not trivial to de-identify the patient, healthcare providers, organization, location, etc. Pseudonymization requires persisten mapping tables between the data and its psudonymized version.
A de-identification tool would help the efforts of various parties to make HL7 example instances available to the wider community for testing purposes.