http://hl7.org/fhir/us/core/StructureDefinition/uscdi-requirement|8.0.0-ballot
**This extension is only used in the US Core Implementation Guide''s Profile StructureDefinition elements.** It flags elements that are *Additional* USCDI Requirements for certified systems. In other words, elements that are not marked as Must Support but are required for ONC Health IT certification testing. See the [Conformance page](general-requirements.html) for more information.