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"/> <date value="2022-09-14T03:23:03-06:00"/> <publisher value="FHIR Project team"/> <contact> <telecom> <system value="url"/> <value value="http://hl7.org/fhir"/> </telecom> </contact> <description value="Structure Definition Use Codes / Keywords"/> <caseSensitive value="true"/> <valueSet value="http://terminology.hl7.org/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>