This code system http://terminology.hl7.org/CodeSystem/definition-use defines the following codes:

CodeDisplayDefinition
fhir-structure FHIR StructureThis structure is defined as part of the base FHIR Specification
custom-resource Custom ResourceThis structure is intended to be treated like a FHIR resource (e.g. on the FHIR API)
dam Domain Analysis ModelThis structure captures an analysis of a domain
wire-format Wire FormatThis structure represents and existing structure (e.g. CDA, HL7 v2)
archetype Domain Analysis ModelThis structure captures an analysis of a domain
template TemplateThis structure is a template (n.b: 'template' has many meanings)
<status value="active"/><experimental value="false"/><description value="Structure Definition Use Codes / Keywords"/><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/definition-use"/><content value="complete"/><concept><code value="fhir-structure"/><display value="FHIR Structure"/><definition value="This structure is defined as part of the base FHIR Specification"/></concept><concept><code value="custom-resource"/><display value="Custom Resource"/><definition value="This structure is intended to be treated like a FHIR resource (e.g. on the FHIR API)"/></concept><concept><code value="dam"/><display value="Domain Analysis Model"/><definition value="This structure captures an analysis of a domain"/></concept><concept><code value="wire-format"/><display value="Wire Format"/><definition value="This structure represents and existing structure (e.g. CDA, HL7 v2)"/></concept><concept><code value="archetype"/><display value="Domain Analysis Model"/><definition value="This structure captures an analysis of a domain"/></concept><concept><code value="template"/><display value="Template"/><definition value="This structure is a template (n.b: 'template' has many meanings)"/></concept></CodeSystem>