US Core Race Extension - Definitions - US Core Implementation Guide v7.0.0

This page is part of the US Core (v7.0.0: STU7) based on FHIR (HL7® FHIR® Standard) R4. This is the current published version in its permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions

Extension: USCoreRaceExtension - Detailed Descriptions

Page standards status: Trial-use

Maturity Level: 3

Definitions for the us-core-race extension.

Differential Elements Table
Key Elements Table
Snapshot Elements Table

Guidance on how to interpret the contents of this table can be found here

0. Extension
Definition	Concepts classifying the person into a named category of humans sharing common history, traits, geographical origin or nationality. The race codes used to represent these concepts are based upon the CDC Race and Ethnicity Code Set Version 1.0 which includes over 900 concepts for representing race and ethnicity of which 921 reference race. The race concepts are grouped by and pre-mapped to the 5 OMB race categories: American Indian or Alaska Native Asian Black or African American Native Hawaiian or Other Pacific Islander White.
Short	US Core Race Extension
Control	0..1 This element is affected by the following invariants: us-core-23
Invariants	us-core-23: If "ASKU" or "UNK" are present, then no other OMB race categories can be present. (`extension.where(url = 'ombCategory').value.where(code in 'ASKU'\|'UNK').exists() implies extension.where(url = 'ombCategory').count() = 1`)
2. Extension.extension
Control	1..?
Slicing	This element introduces a set of slices on `Extension.extension`. The slices are unordered and Open, and can be differentiated using the following discriminators: value @ url
4. Extension.extension:ombCategory
Slice Name	ombCategory
Definition	The 5 race category codes according to the OMB Standards for Maintaining, Collecting, and Presenting Federal Data on Race and Ethnicity, Statistical Policy Directive No. 15, as revised, October 30, 1997.
Short	American Indian or Alaska Native\|Asian\|Black or African American\|Native Hawaiian or Other Pacific Islander\|White
Control	0..6
Type	Extension
Must Support	true
6. Extension.extension:ombCategory.url
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Fixed Value	`ombCategory`
8. Extension.extension:ombCategory.value[x]
Control	1..1
Binding	The codes SHALL be taken from OMB Race Categories (required to `http://hl7.org/fhir/us/core/ValueSet/omb-race-category`) The 5 race category codes according to the OMB Standards for Maintaining, Collecting, and Presenting Federal Data on Race and Ethnicity, Statistical Policy Directive No. 15, as revised, October 30, 1997.
Type	Coding
[x] Note	See Choice of Data Types for further information about how to use [x]
10. Extension.extension:detailed
Slice Name	detailed
Definition	The 900+ CDC race codes that are grouped under one of the 5 OMB race category codes:.
Short	Extended race codes
Control	0..*
Type	Extension
12. Extension.extension:detailed.url
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Fixed Value	`detailed`
14. Extension.extension:detailed.value[x]
Control	1..1
Binding	The codes SHALL be taken from Detailed Race (required to `http://hl7.org/fhir/us/core/ValueSet/detailed-race`)
Type	Coding
[x] Note	See Choice of Data Types for further information about how to use [x]
16. Extension.extension:text
Slice Name	text
Definition	Plain text representation of the race concept(s).
Short	Race Text
Control	1..1
Type	Extension
Must Support	true
18. Extension.extension:text.url
Control	1..1
Type	uri
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Fixed Value	`text`
20. Extension.extension:text.value[x]
Control	1..1
Type	string
[x] Note	See Choice of Data Types for further information about how to use [x]
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
22. Extension.url
Control	1..1
Fixed Value	`http://hl7.org/fhir/us/core/StructureDefinition/us-core-race`
24. Extension.value[x]
Control	0..0

Guidance on how to interpret the contents of this table can be found here

0. Extension
Definition	Concepts classifying the person into a named category of humans sharing common history, traits, geographical origin or nationality. The race codes used to represent these concepts are based upon the CDC Race and Ethnicity Code Set Version 1.0 which includes over 900 concepts for representing race and ethnicity of which 921 reference race. The race concepts are grouped by and pre-mapped to the 5 OMB race categories: American Indian or Alaska Native Asian Black or African American Native Hawaiian or Other Pacific Islander White. Optional Extension Element - found in all resources.
Short	US Core Race ExtensionOptional Extensions Element
Control	0..1* This element is affected by the following invariants: ele-1, us-core-23
Is Modifier	false
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count())) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`) us-core-23: If "ASKU" or "UNK" are present, then no other OMB race categories can be present. (`extension.where(url = 'ombCategory').value.where(code in 'ASKU'\|'UNK').exists() implies extension.where(url = 'ombCategory').count() = 1`) ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
2. Extension.extension
Definition	An Extension 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 manageable, 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.
Short	ExtensionAdditional content defined by implementations
Comments	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.
Control	10..*
Type	Extension
Is Modifier	false
Summary	false
Alternate Names	extensions, user content
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count())) ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
Slicing	This element introduces a set of slices on `Extension.extension`. The slices are unordered and Open, and can be differentiated using the following discriminators: value @ url
4. Extension.extension:ombCategory
Slice Name	ombCategory
Definition	The 5 race category codes according to the OMB Standards for Maintaining, Collecting, and Presenting Federal Data on Race and Ethnicity, Statistical Policy Directive No. 15, as revised, October 30, 1997.
Short	American Indian or Alaska Native\|Asian\|Black or African American\|Native Hawaiian or Other Pacific Islander\|WhiteAdditional content defined by implementations
Control	0..6*
Type	Extension
Is Modifier	false
Must Support	true
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count())) ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
6. Extension.extension:ombCategory.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
Fixed Value	`ombCategory`
8. Extension.extension:ombCategory.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Short	Value of extension
Control	10..1
Binding	The codes SHALL be taken from For codes, see OMB Race Categories (required to `http://hl7.org/fhir/us/core/ValueSet/omb-race-category`) The 5 race category codes according to the OMB Standards for Maintaining, Collecting, and Presenting Federal Data on Race and Ethnicity, Statistical Policy Directive No. 15, as revised, October 30, 1997.
Type	Coding, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, SampledData, id, positiveInt, Distance, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, CodeableConcept, ParameterDefinition, dateTime, code, string, Contributor, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, Signature, unsignedInt, time
[x] Note	See Choice of Data Types for further information about how to use [x]
Is Modifier	false
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
10. Extension.extension:detailed
Slice Name	detailed
Definition	The 900+ CDC race codes that are grouped under one of the 5 OMB race category codes:.
Short	Extended race codesAdditional content defined by implementations
Control	0..*
Type	Extension
Is Modifier	false
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count())) ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
12. Extension.extension:detailed.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
Fixed Value	`detailed`
14. Extension.extension:detailed.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Short	Value of extension
Control	10..1
Binding	The codes SHALL be taken from For codes, see Detailed Race (required to `http://hl7.org/fhir/us/core/ValueSet/detailed-race`)
Type	Coding, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, SampledData, id, positiveInt, Distance, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, CodeableConcept, ParameterDefinition, dateTime, code, string, Contributor, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, Signature, unsignedInt, time
[x] Note	See Choice of Data Types for further information about how to use [x]
Is Modifier	false
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
16. Extension.extension:text
Slice Name	text
Definition	Plain text representation of the race concept(s).
Short	Race TextAdditional content defined by implementations
Control	10..1*
Type	Extension
Is Modifier	false
Must Support	true
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count())) ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
18. Extension.extension:text.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
Fixed Value	`text`
20. Extension.extension:text.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Short	Value of extension
Control	10..1
Type	string, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, Coding, SampledData, id, positiveInt, Distance, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, CodeableConcept, ParameterDefinition, dateTime, code, Contributor, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, Signature, unsignedInt, time
[x] Note	See Choice of Data Types for further information about how to use [x]
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
22. Extension.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Is Modifier	false
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
Fixed Value	`http://hl7.org/fhir/us/core/StructureDefinition/us-core-race`
24. Extension.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Short	Value of extension
Control	0..01
Type	Choice of: base64Binary, boolean, canonical, code, date, dateTime, decimal, id, instant, integer, markdown, oid, positiveInt, string, time, unsignedInt, uri, url, uuid, Address, Age, Annotation, Attachment, CodeableConcept, Coding, ContactPoint, Count, Distance, Duration, HumanName, Identifier, Money, Period, Quantity, Range, Ratio, Reference, SampledData, Signature, Timing, ContactDetail, Contributor, DataRequirement, Expression, ParameterDefinition, RelatedArtifact, TriggerDefinition, UsageContext, Dosage, Meta
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))

Guidance on how to interpret the contents of this table can be found here

0. Extension
Definition	Concepts classifying the person into a named category of humans sharing common history, traits, geographical origin or nationality. The race codes used to represent these concepts are based upon the CDC Race and Ethnicity Code Set Version 1.0 which includes over 900 concepts for representing race and ethnicity of which 921 reference race. The race concepts are grouped by and pre-mapped to the 5 OMB race categories: American Indian or Alaska Native Asian Black or African American Native Hawaiian or Other Pacific Islander White.
Short	US Core Race Extension
Control	0..1 This element is affected by the following invariants: ele-1, us-core-23
Is Modifier	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`) us-core-23: If "ASKU" or "UNK" are present, then no other OMB race categories can be present. (`extension.where(url = 'ombCategory').value.where(code in 'ASKU'\|'UNK').exists() implies extension.where(url = 'ombCategory').count() = 1`)
2. Extension.id
Definition	Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short	Unique id for inter-element referencing
Control	0..1
Type	string
Is Modifier	false
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
4. Extension.extension
Definition	An Extension
Short	Extension
Control	1..*
Type	Extension
Is Modifier	false
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
Slicing	This element introduces a set of slices on `Extension.extension`. The slices are unordered and Open, and can be differentiated using the following discriminators: value @ url
6. Extension.extension:ombCategory
Slice Name	ombCategory
Definition	The 5 race category codes according to the OMB Standards for Maintaining, Collecting, and Presenting Federal Data on Race and Ethnicity, Statistical Policy Directive No. 15, as revised, October 30, 1997.
Short	American Indian or Alaska Native\|Asian\|Black or African American\|Native Hawaiian or Other Pacific Islander\|White
Control	0..6
Type	Extension
Is Modifier	false
Must Support	true
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
8. Extension.extension:ombCategory.id
Definition	Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short	Unique id for inter-element referencing
Control	0..1
Type	string
Is Modifier	false
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
10. Extension.extension:ombCategory.extension
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 manageable, 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.
Short	Additional content defined by implementations
Comments	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.
Control	0..*
Type	Extension
Is Modifier	false
Summary	false
Alternate Names	extensions, user content
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
Slicing	This element introduces a set of slices on `Extension.extension.extension`. The slices are unordered and Open, and can be differentiated using the following discriminators: value @ url
12. Extension.extension:ombCategory.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
Fixed Value	`ombCategory`
14. Extension.extension:ombCategory.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Short	Value of extension
Control	1..1
Binding	The codes SHALL be taken from OMB Race Categories (required to `http://hl7.org/fhir/us/core/ValueSet/omb-race-category`) The 5 race category codes according to the OMB Standards for Maintaining, Collecting, and Presenting Federal Data on Race and Ethnicity, Statistical Policy Directive No. 15, as revised, October 30, 1997.
Type	Coding
[x] Note	See Choice of Data Types for further information about how to use [x]
Is Modifier	false
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
16. Extension.extension:detailed
Slice Name	detailed
Definition	The 900+ CDC race codes that are grouped under one of the 5 OMB race category codes:.
Short	Extended race codes
Control	0..*
Type	Extension
Is Modifier	false
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
18. Extension.extension:detailed.id
Definition	Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short	Unique id for inter-element referencing
Control	0..1
Type	string
Is Modifier	false
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
20. Extension.extension:detailed.extension
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 manageable, 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.
Short	Additional content defined by implementations
Comments	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.
Control	0..*
Type	Extension
Is Modifier	false
Summary	false
Alternate Names	extensions, user content
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
Slicing	This element introduces a set of slices on `Extension.extension.extension`. The slices are unordered and Open, and can be differentiated using the following discriminators: value @ url
22. Extension.extension:detailed.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
Fixed Value	`detailed`
24. Extension.extension:detailed.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Short	Value of extension
Control	1..1
Binding	The codes SHALL be taken from Detailed Race (required to `http://hl7.org/fhir/us/core/ValueSet/detailed-race`)
Type	Coding
[x] Note	See Choice of Data Types for further information about how to use [x]
Is Modifier	false
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
26. Extension.extension:text
Slice Name	text
Definition	Plain text representation of the race concept(s).
Short	Race Text
Control	1..1
Type	Extension
Is Modifier	false
Must Support	true
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
28. Extension.extension:text.id
Definition	Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Short	Unique id for inter-element referencing
Control	0..1
Type	string
Is Modifier	false
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
30. Extension.extension:text.extension
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 manageable, 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.
Short	Additional content defined by implementations
Comments	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.
Control	0..*
Type	Extension
Is Modifier	false
Summary	false
Alternate Names	extensions, user content
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`) ext-1: Must have either extensions or value[x], not both (`extension.exists() != value.exists()`)
Slicing	This element introduces a set of slices on `Extension.extension.extension`. The slices are unordered and Open, and can be differentiated using the following discriminators: value @ url
32. Extension.extension:text.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
Fixed Value	`text`
34. Extension.extension:text.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Short	Value of extension
Control	1..1
Type	string
[x] Note	See Choice of Data Types for further information about how to use [x]
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
36. Extension.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Short	identifies the meaning of the extension
Comments	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.
Control	1..1
Type	uri
Is Modifier	false
XML Format	In the XML format, this property is represented as an attribute.
Summary	false
Fixed Value	`http://hl7.org/fhir/us/core/StructureDefinition/us-core-race`
38. Extension.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Short	Value of extension
Control	0..0
Type	Choice of: base64Binary, boolean, canonical, code, date, dateTime, decimal, id, instant, integer, markdown, oid, positiveInt, string, time, unsignedInt, uri, url, uuid, Address, Age, Annotation, Attachment, CodeableConcept, Coding, ContactPoint, Count, Distance, Duration, HumanName, Identifier, Money, Period, Quantity, Range, Ratio, Reference, SampledData, Signature, Timing, ContactDetail, Contributor, DataRequirement, Expression, ParameterDefinition, RelatedArtifact, TriggerDefinition, UsageContext, Dosage, Meta
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	false
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)