The Office of the National Coordinator for Health IT has recently updated its health IT certification criteria, necessitating updates to various FHIR R4 resources. Due to the nature of these updates, developers using FHIR R4 resources in their applications and services should plan to support both pre-update and post-update versions of the resources. When available, documentation for post-update versions will be published to the specifications page (the page you're on right now). No updates to existing DSTU2 or STU3 resources are planned at this time.