In the Vocabulary WG main call on 28 October 2021 (minutes: https://confluence.hl7.org/pages/viewpage.action?pageId=79516234) , a proposal to Transfer the Using X (extenal code system) with FHIR pages from the FHIR core specification to HL7 Terminology (THO) was presented and voted for.

This ticket address implementation of the changes related to the core FHIR specification. Specifically, to:

• Remove the HTML pages from the FHIR CI build.
• Add a note to the Defined Externally tab in the FHIR specification asserting that use of externally defined code systems with FHIR and other HL7 Standards is authoritatively described in THO along with other information about external terminologies.
• Update the Using X with FHIR pages link titles to reference permalinks to the new Using X With HL7 Standards in THO.