Primary Coding
http://fhir.patientsknowbest.com/structuredefinition/primary-coding
https://www.hl7.org/fhir/STU3/structuredefinition.html
description
Coded data provided via HL7 can contain a primary and alternate coding.
This extension indicates which coding was primary when both codings are returned in a FHIR element.
The absence of this extension on a coding should be interpreted as false.
type
Extension
element type
Boolean