One of the RegenCHOICE fields
Unique Regenerative Relationship Identifier.
This ID supplements the CanNum by providing a universally unique identifier that can be shared between different users.
How this is to be done remains to be decided. The aim is to have an identifier that can be generated on either side by the other side providing their RGC identifier, but that does not allow either side to discover the RGCID of the other from the URRI.
For demo purposes, this requirement can be relaxed, and a simple composite of RGCIDs can be used.