Nationality - Definitions - HL7 PT FHIR Implementation Guide: Example IG Release 1

HL7 PT FHIR Implementation Guide: Example IG Release 1 | STU1, published by HL7 Portugal. This guide is not an authorized publication; it is the continuous build for version 0.0.1 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/hl7-pt/core/ and changes regularly. See the Directory of published versions

Extension: Nationality - Detailed Descriptions

Active as of 2024-09-23

Definitions for the a4126b30-e00e-451a-830c-4db050c60cdf 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	Extension for nationality in Portugal
2. Extension.extension:code
Slice Name	code
Control	0..1
4. Extension.extension:code.extension
Control	0..0
6. Extension.extension:code.url
Fixed Value	`code`
8. Extension.extension:code.value[x]
Binding	Unless not suitable, these codes SHALL be taken from Iso3166-1-2 (extensible to `http://hl7.org/fhir/ValueSet/iso3166-1-2`) This value set defines the ISO 3166 Part 1 2-letter codes
Type	CodeableConcept
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
10. Extension.extension:code.value[x].coding
Binding	Unless not suitable, these codes SHALL be taken from Iso3166-1-2 (extensible to `http://hl7.org/fhir/ValueSet/iso3166-1-2`) This value set defines the ISO 3166 Part 1 2-letter codes
12. Extension.extension:code.value[x].coding.system
14. Extension.extension:code.value[x].coding.code
16. Extension.extension:code.value[x].coding.display
18. Extension.extension:period
Slice Name	period
Control	0..1
20. Extension.extension:period.extension
Control	0..0
22. Extension.extension:period.url
Fixed Value	`period`
24. Extension.extension:period.value[x]
Type	Period
[x] Note	SeeChoice of Data Typesfor further information about how to use [x]
26. Extension.url
Fixed Value	`http://hl7.pt/fhir/core/StructureDefinition/a4126b30-e00e-451a-830c-4db050c60cdf`
28. Extension.value[x]
Control	0..0

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

0. Extension
Definition	Extension for nationality in Portugal Optional Extension Element - found in all resources.
Short	ExtensionOptional Extensions Element
Control	0..* This element is affected by the following invariants: ele-1
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()`) ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
2. Extension.extension:code
Slice Name	code
Definition	An Extension
Short	ExtensionAdditional content defined by implementations
Control	0..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())
4. Extension.extension:code.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	0..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 areUnordered and Open, and can be differentiated using the following discriminators: value @ url
6. Extension.extension:code.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	`code`
8. Extension.extension:code.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..1
Binding	Unless not suitable, these codes SHALL be taken from For codes, see Iso3166-1-2 (extensible to `http://hl7.org/fhir/ValueSet/iso3166-1-2`) This value set defines the ISO 3166 Part 1 2-letter codes
Type	CodeableConcept, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, Coding, SampledData, id, positiveInt, Distance, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, 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	SeeChoice of Data Typesfor 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:code.value[x].coding
Definition	A reference to a code defined by a terminology system.
Short	Code defined by a terminology system
Comments	Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.
Control	0..*
Binding	Unless not suitable, these codes SHALL be taken from For codes, see Iso3166-1-2 (extensible to `http://hl7.org/fhir/ValueSet/iso3166-1-2`) This value set defines the ISO 3166 Part 1 2-letter codes
Type	Coding
Is Modifier	false
Summary	true
Requirements	Allows for alternative encodings within a code system, and translations to other code systems.
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
12. Extension.extension:code.value[x].coding.system
Definition	The identification of the code system that defines the meaning of the symbol in the code.
Short	Identity of the terminology system
Comments	The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously.
Control	0..1
Type	uri
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	true
Requirements	Need to be unambiguous about the source of the definition of the symbol.
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
14. Extension.extension:code.value[x].coding.code
Definition	A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Short	Symbol in syntax defined by the system
Control	0..1
Type	code
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	true
Requirements	Need to refer to a particular code in the system.
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
16. Extension.extension:code.value[x].coding.display
Definition	A representation of the meaning of the code in the system, following the rules of the system.
Short	Representation defined by the system
Control	0..1
Type	string
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	true
Requirements	Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Invariants	ele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
18. Extension.extension:period
Slice Name	period
Definition	An Extension
Short	ExtensionAdditional content defined by implementations
Control	0..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())
20. Extension.extension:period.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	0..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 areUnordered and Open, and can be differentiated using the following discriminators: value @ url
22. Extension.extension:period.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	`period`
24. Extension.extension:period.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..1
Type	Period, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, Coding, SampledData, id, positiveInt, Distance, 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	SeeChoice of Data Typesfor 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.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.pt/fhir/core/StructureDefinition/a4126b30-e00e-451a-830c-4db050c60cdf`
28. 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	Extension for nationality in Portugal
Short	Extension
Control	0..* This element is affected by the following invariants: ele-1
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()`)
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	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`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
6. Extension.extension:code
Slice Name	code
Definition	An Extension
Short	Extension
Control	0..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()`)
8. Extension.extension:code.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:code.extension
Definition	An Extension
Short	Extension
Control	0..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()`)
Slicing	This element introduces a set of slices on `Extension.extension.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
12. Extension.extension:code.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	`code`
14. Extension.extension:code.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..1
Binding	Unless not suitable, these codes SHALL be taken from Iso3166-1-2 (extensible to `http://hl7.org/fhir/ValueSet/iso3166-1-2`) This value set defines the ISO 3166 Part 1 2-letter codes
Type	CodeableConcept
[x] Note	SeeChoice of Data Typesfor 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:code.value[x].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
18. Extension.extension:code.value[x].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.value[x].extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
20. Extension.extension:code.value[x].coding
Definition	A reference to a code defined by a terminology system.
Short	Code defined by a terminology system
Comments	Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.
Control	0..*
Binding	Unless not suitable, these codes SHALL be taken from Iso3166-1-2 (extensible to `http://hl7.org/fhir/ValueSet/iso3166-1-2`) This value set defines the ISO 3166 Part 1 2-letter codes
Type	Coding
Is Modifier	false
Summary	true
Requirements	Allows for alternative encodings within a code system, and translations to other code systems.
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
22. Extension.extension:code.value[x].coding.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
24. Extension.extension:code.value[x].coding.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.value[x].coding.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
26. Extension.extension:code.value[x].coding.system
Definition	The identification of the code system that defines the meaning of the symbol in the code.
Short	Identity of the terminology system
Comments	The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously.
Control	0..1
Type	uri
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	true
Requirements	Need to be unambiguous about the source of the definition of the symbol.
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
28. Extension.extension:code.value[x].coding.version
Definition	The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.
Short	Version of the system - if relevant
Comments	Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.
Note	This is a business version Id, not a resource version Id (see discussion)
Control	0..1
Type	string
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	true
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
30. Extension.extension:code.value[x].coding.code
Definition	A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).
Short	Symbol in syntax defined by the system
Control	0..1
Type	code
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	true
Requirements	Need to refer to a particular code in the system.
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
32. Extension.extension:code.value[x].coding.display
Definition	A representation of the meaning of the code in the system, following the rules of the system.
Short	Representation defined by the system
Control	0..1
Type	string
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	true
Requirements	Need to be able to carry a human-readable meaning of the code for readers that do not know the system.
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
34. Extension.extension:code.value[x].coding.userSelected
Definition	Indicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays).
Short	If this coding was chosen directly by the user
Comments	Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.
Control	0..1
Type	boolean
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	true
Requirements	This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
36. Extension.extension:code.value[x].text
Definition	A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user.
Short	Plain text representation of the concept
Comments	Very often the text is the same as a displayName of one of the codings.
Control	0..1
Type	string
Is Modifier	false
Primitive Value	This primitive element may be present, or absent, or replaced by an extension
Summary	true
Requirements	The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source.
Invariants	ele-1: All FHIR elements must have a @value or children (`hasValue() or (children().count() > id.count())`)
38. Extension.extension:period
Slice Name	period
Definition	An Extension
Short	Extension
Control	0..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()`)
40. Extension.extension:period.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
42. Extension.extension:period.extension
Definition	An Extension
Short	Extension
Control	0..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()`)
Slicing	This element introduces a set of slices on `Extension.extension.extension`. The slices areUnordered and Open, and can be differentiated using the following discriminators: value @ url
44. Extension.extension:period.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	`period`
46. Extension.extension:period.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..1
Type	Period
[x] Note	SeeChoice of Data Typesfor 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())`)
48. 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.pt/fhir/core/StructureDefinition/a4126b30-e00e-451a-830c-4db050c60cdf`
50. 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())`)