Following SPECPR-99 and this email string from 2014, the imminent RM 1.0.4 release will include SPECRM-80, which improves the documentation about system_id, which is recorded in the EHR and also in AUDIT_DETAILS, i.e. on each committed version.
In response to this, I have added the following documentation to the Architecture Overview, and will also add further text and hot links to the specific locations in the EHR and Common parts of the RM. It would be useful to know if this agrees with the understanding of openEHR system implementers and users.