ackage (has an ImplementationGuide resource in /package, along with conformance resources, and also contains example resources in /package/example)</li>
        <li><b>Core</b> - contains the conformance related resources for the main FHIR specification (effectively, this is a special type of "conformance" that marks it as the core specification, which could also be inferred from its name such as hl7.fhir.r4.core, but other branches / ballots etc. may vary, so this is simpler than inferring from the name)<