Replace the current Boundary and Relationshp text with the following:
The SupplyRequest resource represents an authorization for a supply to be provided.
The SupplyDelivery resource documents the movement of supply as a result of the SupplyRequest being acted upon.
Details of the actions performed as a result of the SupplyRequest are handled by the Task resource (which may reference the SupplyRequest in `Task.focus`) or by using a messaging or workflow service where the request is explicit or implicit. For further information about this separation of responsibilities, refer to the Fulfillment/Execution (https://www.hl7.org/fhir/request.html#fulfillment) section of the Request pattern.
The SupplyRequest resource is used for inventory management. When requesting medication, substances and devices when there is a patient focus or instructions regarding their use, DeviceRequest or MedicationRequest should be used instead.
For DeviceDispense, MedicationDispense, and BiologicallyDerivedProductDispense [add BDP link], a SupplyRequest does not document the formal association of a device, medication, biologically derived product, or supply item to a patient. The DeviceDispense (or MedicationDispense or BiologicallyDerivceProductDispense) is used to formally document that the device, medication, biologically derived product or supply item is to be used by or for a patient in a medical activity.
Consider moving to an Note/Comment and/or the Scope and usage section:
To determine the purchase date, a search of DeviceRequest, SupplyRequest, DeviceDispense, or SupplyDelivery as defined in an implementation guide can be done , as the context of the use case actually determines which date of either resource is considered the purchase date.