Existing Wording
DiagnosticOrder vs ProcedureRequest

Comments
The definition for both resources needs to be refined to explicitly distinguish when one or the other resource is to be used. The introduction of ProcedureRequest can make this choice more tricky unless there are clear guidelines as to which one to use when.

Grahame's Comments
PC/OO need to discuss this; most requests would obviously be one or the other, but there's a grey zone (e.g. surgery with biopsy or imaging, surgery for imaging)