Will add a new section in the notes of the resource that says: Contained There are two notions of 'contained' in this resource - the generic 'contained' element inherited from DomainResource that allows other resources to be nested inside this ExampleScenario (e.g. Provenance, structureProfiles, or instance or instance.version content).  There's also a containedInstance element on ExampleScenario.instance.  This latter element reflects the nesting of content within the data shared as part of a scenario.  For example, highlighting that an instance initially received on its own (e.g. an Observation) is later conveyed in a Bundle (as a document, message or search response), or potentially a resource that was nested as a 'contained' resource in one instance is available in non-contained form or contained inside a different resource in a separate instance. In short, 'ExampleScenario.contained' is for nesting resources inside the ExampleScenario.  ExampleScenario.instance.containedInstance reflects the nesting of data being transmitted by an ExampleScenario operation as part of the scenario.