FHIR Connectathon 29, Subscriptions: Part 3 - R4B Specification

Detailed walkthrough of the Subscriptions R4 Backport Implementation Guide (IG) and new resources in R4B in preparation for Connectathon 29 (January 2022). IG: http://build.fhir.org/ig/HL7/fhir-sub... R4B: http://hl7.org/fhir/4.3.0-snapshot1/