Existing Wording
E.g., ProcedureRequest/Procedure and DiagnosticOrder/ProcedureRequest

Comments
Certain relationships between resources in FHIR are not defined. For instance, both the ProcedureRequest and Procedure resources pertain to a Procedure. Also a DiagnosticOrder and a ProcedureRequest both pertain to the notion of a 'Request'. The definitions of such relations in FHIR are important. At this time, some of this is done by categorization. Perhaps a more formal approach could be supported as well. Would FHIR consider a shallow hierarchy and the notion of potentially abstract resources?

Grahame's Comments
We have slots to do this in metadata, and work is proceeding to actually do this (Grahame/Bo). That would address this, I think. We can consider abstract resources, but I don't know if they are applicable to this case

Disposition
Pending input from submitter

Disposition Comment
How would adding such a shallow hierarchy provide value at the implementation level? We explored the notion of whether decision support rules would ever be created at a more generic level, but there were no clear use-cases. Because FHIR is focused on implementation, adding hierarchy would need to have clear implementer benefits.