{"abstract":false,"baseDefinition":"http://hl7.org/fhir/StructureDefinition/DataType","contact":[{"telecom":[{"system":"url","value":"http://hl7.org/fhir"}]},{"telecom":[{"system":"url","value":"http://www.hl7.org/Special/committees/fiwg"}]}],"date":"2026-03-29T21:54:20+00:00","derivation":"specialization","description":"Extension Type: Optional Extension Element - found in all resources.","differential":{"element":[{"constraint":[{"expression":"extension.exists() != value.exists()","human":"Must have either extensions or value[x], not both","key":"ext-1","severity":"error","source":"http://hl7.org/fhir/StructureDefinition/Extension"}],"definition":"Optional Extension Element - found in all resources.","id":"Extension","mapping":[{"identity":"rim","map":"N/A"}],"max":"*","min":0,"path":"Extension","short":"Optional Extensions Element"},{"comment":"The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.","definition":"Source of the definition for the extension code - a logical name or a URL.","id":"Extension.url","isSummary":true,"mapping":[{"identity":"rim","map":"N/A"}],"max":"1","min":1,"path":"Extension.url","representation":["xmlAttr"],"short":"identifies the meaning of the extension","type":[{"code":"http://hl7.org/fhirpath/System.String","extension":[{"url":"http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type","valueUrl":"uri"}]}]},{"condition":["ext-1"],"definition":"Value of extension - must be one of a constrained set of the data types (see [Extensibility](extensibility.html) for a list).","id":"Extension.value[x]","isSummary":true,"mapping":[{"identity":"rim","map":"N/A"}],"max":"1","min":0,"path":"Extension.value[x]","short":"Value of extension","type":[{"code":"base64Binary"},{"code":"boolean"},{"code":"canonical"},{"code":"code"},{"code":"date"},{"code":"dateTime"},{"code":"decimal"},{"code":"id"},{"code":"instant"},{"code":"integer"},{"code":"integer64"},{"code":"markdown"},{"code":"oid"},{"code":"positiveInt"},{"code":"string"},{"code":"time"},{"code":"unsignedInt"},{"code":"uri"},{"code":"url"},{"code":"uuid"},{"code":"Address"},{"code":"Age"},{"code":"Annotation"},{"code":"Attachment"},{"code":"CodeableConcept"},{"code":"CodeableReference"},{"code":"Coding"},{"code":"ContactPoint"},{"code":"Count"},{"code":"Distance"},{"code":"Duration"},{"code":"HumanName"},{"code":"Identifier"},{"code":"Money"},{"code":"Period"},{"code":"Quantity"},{"code":"Range"},{"code":"Ratio"},{"code":"RatioRange"},{"code":"Reference"},{"code":"SampledData"},{"code":"Signature"},{"code":"Timing"},{"code":"ContactDetail"},{"code":"DataRequirement"},{"code":"Expression"},{"code":"ParameterDefinition"},{"code":"RelatedArtifact"},{"code":"TriggerDefinition"},{"code":"UsageContext"},{"code":"Availability"},{"code":"ExtendedContactDetail"},{"code":"VirtualServiceDetail"},{"code":"Dosage"},{"code":"Meta"}]}]},"experimental":false,"extension":[{"url":"http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status","valueCode":"normative"},{"url":"http://hl7.org/fhir/StructureDefinition/structuredefinition-normative-version","valueCode":"4.0.0"},{"url":"http://hl7.org/fhir/StructureDefinition/structuredefinition-type-characteristics","valueCode":"can-bind"},{"url":"http://hl7.org/fhir/StructureDefinition/structuredefinition-wg","valueCode":"fhir"}],"fhirVersion":"6.0.0-ballot4","id":"Extension","jurisdiction":[{"coding":[{"code":"001","display":"World","system":"http://unstats.un.org/unsd/methods/m49/m49.htm"}]}],"kind":"complex-type","mapping":[{"identity":"rim","name":"RIM Mapping","uri":"http://hl7.org/v3"}],"name":"Extension","publisher":"HL7 International / FHIR Infrastructure","purpose":"The ability to add extensions in a structured way is what keeps FHIR resources simple.","resourceType":"StructureDefinition","snapshot":{"element":[{"base":{"max":"*","min":0,"path":"Extension"},"constraint":[{"expression":"hasValue() or (children().count() > id.count())","human":"All FHIR elements must have a @value or children","key":"ele-1","severity":"error","source":"http://hl7.org/fhir/StructureDefinition/Element"},{"expression":"extension.exists() != value.exists()","human":"Must have either extensions or value[x], not both","key":"ext-1","severity":"error","source":"http://hl7.org/fhir/StructureDefinition/Extension"}],"definition":"Optional Extension Element - found in all resources.","id":"Extension","isModifier":false,"mapping":[{"identity":"rim","map":"n/a,N/A"}],"max":"*","min":0,"path":"Extension","short":"Optional Extensions Element"},{"base":{"max":"1","min":0,"path":"Element.id"},"condition":["ele-1"],"definition":"Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.","id":"Extension.id","isModifier":false,"isSummary":false,"mapping":[{"identity":"rim","map":"n/a"}],"max":"1","min":0,"path":"Extension.id","representation":["xmlAttr"],"short":"Unique id for inter-element referencing","type":[{"code":"http://hl7.org/fhirpath/System.String","extension":[{"url":"http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type","valueUrl":"string"}]}]},{"alias":["extensions","user content"],"base":{"max":"*","min":0,"path":"Element.extension"},"comment":"There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.","constraint":[{"expression":"hasValue() or (children().count() > id.count())","human":"All FHIR elements must have a @value or children","key":"ele-1","severity":"error","source":"http://hl7.org/fhir/StructureDefinition/Element"}],"definition":"May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and managable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.","id":"Extension.extension","isModifier":false,"isSummary":false,"mapping":[{"identity":"rim","map":"n/a"}],"max":"*","min":0,"path":"Extension.extension","short":"Additional content defined by implementations","slicing":{"description":"Extensions are always sliced by (at least) url","discriminator":[{"path":"url","type":"value"}],"rules":"open"},"type":[{"code":"Extension"}]},{"base":{"max":"1","min":1,"path":"Extension.url"},"comment":"The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.","definition":"Source of the definition for the extension code - a logical name or a URL.","id":"Extension.url","isModifier":false,"isSummary":true,"mapping":[{"identity":"rim","map":"N/A"}],"max":"1","min":1,"path":"Extension.url","representation":["xmlAttr"],"short":"identifies the meaning of the extension","type":[{"code":"http://hl7.org/fhirpath/System.String","extension":[{"url":"http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type","valueUrl":"uri"}]}]},{"base":{"max":"1","min":0,"path":"Extension.value[x]"},"condition":["ext-1"],"constraint":[{"expression":"hasValue() or (children().count() > id.count())","human":"All FHIR elements must have a @value or children","key":"ele-1","severity":"error","source":"http://hl7.org/fhir/StructureDefinition/Element"}],"definition":"Value of extension - must be one of a constrained set of the data types (see [Extensibility](extensibility.html) for a list).","id":"Extension.value[x]","isModifier":false,"isSummary":true,"mapping":[{"identity":"rim","map":"N/A"}],"max":"1","min":0,"path":"Extension.value[x]","short":"Value of extension","type":[{"code":"base64Binary"},{"code":"boolean"},{"code":"canonical"},{"code":"code"},{"code":"date"},{"code":"dateTime"},{"code":"decimal"},{"code":"id"},{"code":"instant"},{"code":"integer"},{"code":"integer64"},{"code":"markdown"},{"code":"oid"},{"code":"positiveInt"},{"code":"string"},{"code":"time"},{"code":"unsignedInt"},{"code":"uri"},{"code":"url"},{"code":"uuid"},{"code":"Address"},{"code":"Age"},{"code":"Annotation"},{"code":"Attachment"},{"code":"CodeableConcept"},{"code":"CodeableReference"},{"code":"Coding"},{"code":"ContactPoint"},{"code":"Count"},{"code":"Distance"},{"code":"Duration"},{"code":"HumanName"},{"code":"Identifier"},{"code":"Money"},{"code":"Period"},{"code":"Quantity"},{"code":"Range"},{"code":"Ratio"},{"code":"RatioRange"},{"code":"Reference"},{"code":"SampledData"},{"code":"Signature"},{"code":"Timing"},{"code":"ContactDetail"},{"code":"DataRequirement"},{"code":"Expression"},{"code":"ParameterDefinition"},{"code":"RelatedArtifact"},{"code":"TriggerDefinition"},{"code":"UsageContext"},{"code":"Availability"},{"code":"ExtendedContactDetail"},{"code":"VirtualServiceDetail"},{"code":"Dosage"},{"code":"Meta"}]}]},"status":"active","text":{"div":"
\r\n\r\n\r\n
NameFlagsCard.TypeDescription & Constraints\"doco\"
\".\"\".\" ExtensionNElementOptional Extensions Element
+ Rule: Must have either extensions or value[x], not both

Elements defined in Ancestors: id, extension
\".\"\".\"\".\" urlΣ1..1uriidentifies the meaning of the extension
\".\"\".\"\".\" value[x]ΣC0..1*Value of extension

\"doco\" Documentation for this format
","status":"generated"},"type":"Extension","url":"http://hl7.org/fhir/StructureDefinition/Extension","version":"6.0.0-ballot4"}