uuid
type: StructureDefinition
node role: treeRoot
id:
  v: uuid
text:
  status:
    v: generated
  div: Primitive type 'uuid'
extension:
  url:
    v: http://hl7.org/fhir/tools/StructureDefinition/xml-namespace
  value: uri
    v: urn:hl7-org:v3
extension:
  url:
    v: http://hl7.org/fhir/tools/StructureDefinition/logical-container
  value: uri
    v: http://hl7.org/cda/stds/core/StructureDefinition/ClinicalDocument
extension:
  url:
    v: http://hl7.org/fhir/StructureDefinition/structuredefinition-type-characteristics
  value: code
    v: can-bind
url:
  v: http://hl7.org/cda/stds/core/StructureDefinition/uuid
version:
  v: 1.0.1
name:
  v: uuid
title:
  v: uuid: DCE Universal Unique Identifier
status:
  v: active
experimental:
  v: false
date:
  v: 2025-10-10T09:58:30+10:00
publisher:
  v: HL7
description:
  v: A globally unique string representing a DCE Universal Unique Identifier (UUID) in the common UUID format that consists of 5 hyphen-separated groups of hexadecimal digits having 8, 4, 4, 4, and 12 places respectively. ***NOTE:*** The output of UUID related programs and functions may use all sorts of forms, upper case, lower case, and with or without the hyphens that group the digits. This variate output must be postprocessed to conform to the HL7 specification, i.e., the hyphens must be inserted for the 8-4-4-4-12 grouping. Historically, CDA also required that all hexadecimal digits must be converted to upper case, but due to real-world issues encountered when enforcing this rule, it has been relaxed to allow for upper or lower case letters. Additionally, FHIR requires that UUID's be communicated using only lower case letters, so for broader compatibility, implementers are encouraged to use lower case letters.
fhir version:
  v: 5.0.0
kind:
  v: primitive-type
abstract:
  v: false
type:
  v: string
base definition:
  v: http://hl7.org/fhir/StructureDefinition/string
  link: http://hl7.org/fhir/StructureDefinition/string
derivation:
  v: constraint
snapshot:
  extension:
    url:
      v: http://hl7.org/fhir/tools/StructureDefinition/snapshot-base-version
    value: string
      v: 5.0.0
  element:
    id:
      v: string
    path:
      v: string
    short:
      v: Primitive Type string
    definition:
      v: A sequence of Unicode characters
    comment:
      v: Note that FHIR strings SHALL NOT exceed 1,048,576 (1024*1024) characters in size
    min:
      v: 0
    max:
      v: *
    base:
      path:
        v: string
      min:
        v: 0
      max:
        v: *
    constraint:
      key:
        v: ele-1
      severity:
        v: error
      human:
        v: All FHIR elements must have a @value or children
      expression:
        v: hasValue() or (children().count() > id.count())
      source:
        v: http://hl7.org/fhir/StructureDefinition/Element
        link: http://hl7.org/fhir/StructureDefinition/Element
    constraint:
      key:
        v: uuid-pattern
      severity:
        v: error
      human:
        v: Must contain 5 hyphen-separated groups of hexadecimal digits having 8, 4, 4, 4, and 12 places respectively.
      expression:
        v: matches('^[0-9A-Za-z]{8}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{12}$')
    is modifier:
      v: false
    is summary:
      v: false
  element:
    id:
      v: string.id
    path:
      v: string.id
    representation:
      v: xmlAttr
    short:
      v: xml:id (or equivalent in JSON)
    definition:
      v: unique id for the element within a resource (for internal references)
    min:
      v: 0
    max:
      v: 0
    base:
      path:
        v: Element.id
      min:
        v: 0
      max:
        v: 1
    type:
      extension:
        value: url
      code:
        v: http://hl7.org/fhirpath/System.String
    is modifier:
      v: false
    is summary:
      v: false
  element:
    id:
      v: string.extension
    path:
      v: string.extension
    short:
      v: Extension
    definition:
      v: An Extension
    min:
      v: 0
    max:
      v: 0
    base:
      path:
        v: Element.extension
      min:
        v: 0
      max:
        v: *
    type:
      code:
        v: Extension
    constraint:
      key:
        v: ele-1
      severity:
        v: error
      human:
        v: All FHIR elements must have a @value or children
      expression:
        v: hasValue() or (children().count() > id.count())
      source:
        v: http://hl7.org/fhir/StructureDefinition/Element
        link: http://hl7.org/fhir/StructureDefinition/Element
    constraint:
      key:
        v: ext-1
      severity:
        v: error
      human:
        v: Must have either extensions or value[x], not both
      expression:
        v: extension.exists() != value.exists()
      source:
        v: http://hl7.org/fhir/StructureDefinition/Extension
        link: http://hl7.org/fhir/StructureDefinition/Extension
    is modifier:
      v: false
    is summary:
      v: false
  element:
    id:
      v: string.value
    path:
      v: string.value
    representation:
      v: xmlAttr
    short:
      v: Primitive value for string
    definition:
      v: The actual value
    min:
      v: 0

url
v: string

v: 1

path:
  v: string.value
min:
  v: 0
max:
  v: 1

extension:
  url:
    v: http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type
  value: url
    v: string
extension:
  url:
    v: http://hl7.org/fhir/StructureDefinition/regex
  value: string
    v: ^[\s\S]+$
code:
  v: http://hl7.org/fhirpath/System.String

v: 1048576

v: false

v: false

element:
  id:
    v: string
  path:
    v: string
  constraint:
    key:
      v: uuid-pattern
    severity:
      v: error
    human:
      v: Must contain 5 hyphen-separated groups of hexadecimal digits having 8, 4, 4, 4, and 12 places respectively.
    expression:
      v: matches('^[0-9A-Za-z]{8}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{4}-[0-9A-Za-z]{12}$')
element:
  id:
    v: string.id
  path:
    v: string.id
  max:
    v: 0
element:
  id:
    v: string.extension
  path:
    v: string.extension
  max:
    v: 0