HL7.FHIR.UV.EXTENSIONS\Resource Derivation Reference - Definitions

This page is part of the FHIR Core Extensions Registry (v0.1.0: Releases Draft) based on FHIR v5.0.0. . For a full list of available versions, see the Directory of published versions

Extension: ResourceDerivationReference - Detailed Descriptions

Page standards status: Trial-use

Maturity Level: 0

Definitions for the derivation-reference extension.

Differential Elements Table
Key Elements Table
Snapshot Elements Table

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

1. Extension
Definition	References a location within a set of source text from which the discrete information described by this Resource/Element was extracted. Optional Extension Element - found in all resources.
Invariants	Defined on this element der-1: Cannot have length if offset is missing. (: extension.where(url='length').exists() implies extension.where(url='offset').exists())
2. Extension.extension:reference
SliceName	reference
Definition	References a location within a set of source text from which the discrete information described by this Resource/Element was extracted.
Control	0..1
3. Extension.extension:reference.extension
Control	0..0
4. Extension.extension:reference.url
Control	0..?
Fixed Value	reference
5. Extension.extension:reference.value[x]
Control	1..?
Type	Reference
[x] Note	See Choice of Data Types for further information about how to use [x]
6. Extension.extension:path
SliceName	path
Definition	Corresponds to the element within the resource containing the text.
Control	0..1
Comments	Follows the FHIRPath expression syntax used for OperationOutcome. If not present, then the resource must either be a Binary or a DocumentReference (with a single content element) and the content is the text represented by the instance or the attachment. If the DocumentReference has more than one 'content', then this path element SHALL be present to distinguish which repetition the derivation occurred from.
7. Extension.extension:path.extension
Control	0..0
8. Extension.extension:path.url
Control	0..?
Fixed Value	path
9. Extension.extension:path.value[x]
Control	1..?
Type	string
[x] Note	See Choice of Data Types for further information about how to use [x]
10. Extension.extension:offset
SliceName	offset
Definition	Indicates the starting position (as a count of characters) within the text where the relevant derivation began.
Control	0..1
Meaning if Missing	If not specified, the location at which derivation started is unknown.
11. Extension.extension:offset.extension
Control	0..0
12. Extension.extension:offset.url
Control	0..?
Fixed Value	offset
13. Extension.extension:offset.value[x]
Control	1..?
Type	integer
[x] Note	See Choice of Data Types for further information about how to use [x]
14. Extension.extension:length
SliceName	length
Definition	Indicates the number of characters following the start position/beginning of the document that was used as part of the derivation process.
Control	0..1
Meaning if Missing	If not specified, the location at which derivation ended is unknown.
15. Extension.extension:length.extension
Control	0..0
16. Extension.extension:length.url
Control	0..?
Fixed Value	length
17. Extension.extension:length.value[x]
Control	1..?
Type	integer
[x] Note	See Choice of Data Types for further information about how to use [x]
18. Extension.url
Fixed Value	http://hl7.org/fhir/StructureDefinition/derivation-reference
19. Extension.value[x]
Control	0..01
[x] Note	See Choice of Data Types for further information about how to use [x]

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

1. Extension
Definition	References a location within a set of source text from which the discrete information described by this Resource/Element was extracted. Optional Extension Element - found in all resources.
Control	0..*
Invariants	Defined on this element der-1: Cannot have length if offset is missing. (: extension.where(url='length').exists() implies extension.where(url='offset').exists()) 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.extension:reference
SliceName	reference
Definition	References a location within a set of source text from which the discrete information described by this Resource/Element was extracted. 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.
Control	0..1*
Type	Extension
Summary	false
Alternate Names	extensions, user content
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.
Invariants	Defined on this element 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())
3. Extension.extension:reference.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 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.
Control	0..0*
Type	Extension
Summary	false
Alternate Names	extensions, user content
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.
Invariants	Defined on this element 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
4. Extension.extension:reference.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
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.
Fixed Value	reference
5. Extension.extension:reference.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Control	10..1 This element is affected by the following invariants: ext-1
Type	Choice of: Reference, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, RatioRange, Coding, SampledData, id, positiveInt, Distance, Availability, integer64, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, ExtendedContactDetail, CodeableConcept, ParameterDefinition, dateTime, code, string, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, CodeableReference, Signature, unsignedInt, time
[x] Note	See Choice of Data Types for further information about how to use [x]
Summary	false
Invariants	Defined on this element ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
6. Extension.extension:path
SliceName	path
Definition	Corresponds to the element within the resource containing the text. 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.
Control	0..1*
Type	Extension
Summary	false
Alternate Names	extensions, user content
Comments	Follows the FHIRPath expression syntax used for OperationOutcome. If not present, then the resource must either be a Binary or a DocumentReference (with a single content element) and the content is the text represented by the instance or the attachment. If the DocumentReference has more than one 'content', then this path element SHALL be present to distinguish which repetition the derivation occurred from. 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.
Invariants	Defined on this element 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())
7. Extension.extension:path.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 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.
Control	0..0*
Type	Extension
Summary	false
Alternate Names	extensions, user content
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.
Invariants	Defined on this element 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
8. Extension.extension:path.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
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.
Fixed Value	path
9. Extension.extension:path.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Control	10..1 This element is affected by the following invariants: ext-1
Type	Choice of: string, date, Meta, Address, Attachment, integer, Count, DataRequirement, Dosage, uuid, Identifier, RatioRange, Coding, SampledData, id, positiveInt, Distance, Availability, integer64, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, ExtendedContactDetail, CodeableConcept, ParameterDefinition, dateTime, code, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, CodeableReference, Signature, unsignedInt, time
[x] Note	See Choice of Data Types for further information about how to use [x]
Summary	false
Invariants	Defined on this element ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
10. Extension.extension:offset
SliceName	offset
Definition	Indicates the starting position (as a count of characters) within the text where the relevant derivation began. 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.
Control	0..1*
Type	Extension
Summary	false
Alternate Names	extensions, user content
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.
Invariants	Defined on this element 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())
11. Extension.extension:offset.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 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.
Control	0..0*
Type	Extension
Summary	false
Alternate Names	extensions, user content
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.
Invariants	Defined on this element 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:offset.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
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.
Fixed Value	offset
13. Extension.extension:offset.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Control	10..1 This element is affected by the following invariants: ext-1
Type	Choice of: integer, date, Meta, Address, Attachment, Count, DataRequirement, Dosage, uuid, Identifier, RatioRange, Coding, SampledData, id, positiveInt, Distance, Availability, integer64, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, ExtendedContactDetail, CodeableConcept, ParameterDefinition, dateTime, code, string, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, CodeableReference, Signature, unsignedInt, time
[x] Note	See Choice of Data Types for further information about how to use [x]
Summary	false
Invariants	Defined on this element ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
14. Extension.extension:length
SliceName	length
Definition	Indicates the number of characters following the start position/beginning of the document that was used as part of the derivation process. 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.
Control	0..1*
Type	Extension
Summary	false
Alternate Names	extensions, user content
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.
Invariants	Defined on this element 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())
15. Extension.extension:length.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 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.
Control	0..0*
Type	Extension
Summary	false
Alternate Names	extensions, user content
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.
Invariants	Defined on this element 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
16. Extension.extension:length.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
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.
Fixed Value	length
17. Extension.extension:length.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Control	10..1 This element is affected by the following invariants: ext-1
Type	Choice of: integer, date, Meta, Address, Attachment, Count, DataRequirement, Dosage, uuid, Identifier, RatioRange, Coding, SampledData, id, positiveInt, Distance, Availability, integer64, Period, Duration, canonical, Range, RelatedArtifact, base64Binary, UsageContext, Timing, decimal, ExtendedContactDetail, CodeableConcept, ParameterDefinition, dateTime, code, string, oid, instant, ContactPoint, HumanName, Money, markdown, Ratio, Age, Reference, TriggerDefinition, Quantity, uri, url, Annotation, ContactDetail, boolean, Expression, CodeableReference, Signature, unsignedInt, time
[x] Note	See Choice of Data Types for further information about how to use [x]
Summary	false
Invariants	Defined on this element ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
18. Extension.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
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.
Fixed Value	http://hl7.org/fhir/StructureDefinition/derivation-reference
19. Extension.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Control	0..01 This element is affected by the following invariants: ext-1
Type	Choice of: base64Binary, boolean, canonical, code, date, dateTime, decimal, id, instant, integer, integer64, markdown, oid, positiveInt, string, time, unsignedInt, uri, url, uuid, Address, Age, Annotation, Attachment, CodeableConcept, CodeableReference, Coding, ContactPoint, Count, Distance, Duration, HumanName, Identifier, Money, Period, Quantity, Range, Ratio, RatioRange, Reference, SampledData, Signature, Timing, ContactDetail, DataRequirement, Expression, ParameterDefinition, RelatedArtifact, TriggerDefinition, UsageContext, Availability, ExtendedContactDetail, Dosage, Meta
[x] Note	See Choice of Data Types for further information about how to use [x]
Summary	false
Invariants	Defined on this element 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.

1. Extension
Definition	References a location within a set of source text from which the discrete information described by this Resource/Element was extracted.
Control	0..*
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.
Control	0..1 This element is affected by the following invariants: ele-1
Type	id
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
3. 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 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.
Control	0..*
Type	Extension
Summary	false
Alternate Names	extensions, user content
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.
Invariants	Defined on this element 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:reference
SliceName	reference
Definition	References a location within a set of source text from which the discrete information described by this Resource/Element was extracted.
Control	0..1
Type	Extension
Summary	false
Invariants	Defined on this element 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())
5. Extension.extension:reference.id
Definition	Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Control	0..1 This element is affected by the following invariants: ele-1
Type	id
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
6. Extension.extension:reference.extension
Definition	An Extension
Control	0..0
Type	Extension
Summary	false
Invariants	Defined on this element 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
7. Extension.extension:reference.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
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.
Fixed Value	reference
8. Extension.extension:reference.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Control	1..1 This element is affected by the following invariants: ext-1
Type	Reference
[x] Note	See Choice of Data Types for further information about how to use [x]
Summary	false
Invariants	Defined on this element ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
9. Extension.extension:path
SliceName	path
Definition	Corresponds to the element within the resource containing the text.
Control	0..1
Type	Extension
Summary	false
Comments	Follows the FHIRPath expression syntax used for OperationOutcome. If not present, then the resource must either be a Binary or a DocumentReference (with a single content element) and the content is the text represented by the instance or the attachment. If the DocumentReference has more than one 'content', then this path element SHALL be present to distinguish which repetition the derivation occurred from.
Invariants	Defined on this element 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())
10. Extension.extension:path.id
Definition	Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Control	0..1 This element is affected by the following invariants: ele-1
Type	id
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
11. Extension.extension:path.extension
Definition	An Extension
Control	0..0
Type	Extension
Summary	false
Invariants	Defined on this element 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:path.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
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.
Fixed Value	path
13. Extension.extension:path.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Control	1..1 This element is affected by the following invariants: ext-1
Type	string
[x] Note	See Choice of Data Types for further information about how to use [x]
Summary	false
Invariants	Defined on this element ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
14. Extension.extension:offset
SliceName	offset
Definition	Indicates the starting position (as a count of characters) within the text where the relevant derivation began.
Control	0..1
Type	Extension
Summary	false
Invariants	Defined on this element 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())
15. Extension.extension:offset.id
Definition	Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Control	0..1 This element is affected by the following invariants: ele-1
Type	id
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
16. Extension.extension:offset.extension
Definition	An Extension
Control	0..0
Type	Extension
Summary	false
Invariants	Defined on this element 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
17. Extension.extension:offset.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
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.
Fixed Value	offset
18. Extension.extension:offset.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Control	1..1 This element is affected by the following invariants: ext-1
Type	integer
[x] Note	See Choice of Data Types for further information about how to use [x]
Summary	false
Invariants	Defined on this element ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
19. Extension.extension:length
SliceName	length
Definition	Indicates the number of characters following the start position/beginning of the document that was used as part of the derivation process.
Control	0..1
Type	Extension
Summary	false
Invariants	Defined on this element 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:length.id
Definition	Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Control	0..1 This element is affected by the following invariants: ele-1
Type	id
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
21. Extension.extension:length.extension
Definition	An Extension
Control	0..0
Type	Extension
Summary	false
Invariants	Defined on this element 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:length.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
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.
Fixed Value	length
23. Extension.extension:length.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Control	1..1 This element is affected by the following invariants: ext-1
Type	integer
[x] Note	See Choice of Data Types for further information about how to use [x]
Summary	false
Invariants	Defined on this element ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))
24. Extension.url
Definition	Source of the definition for the extension code - a logical name or a URL.
Control	1..1
Type	uri
XML Representation	In the XML format, this property is represented as an attribute.
Summary	false
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.
Fixed Value	http://hl7.org/fhir/StructureDefinition/derivation-reference
25. Extension.value[x]
Definition	Value of extension - must be one of a constrained set of the data types (see Extensibility for a list).
Control	0..0 This element is affected by the following invariants: ext-1
Type	Choice of: base64Binary, boolean, canonical, code, date, dateTime, decimal, id, instant, integer, integer64, markdown, oid, positiveInt, string, time, unsignedInt, uri, url, uuid, Address, Age, Annotation, Attachment, CodeableConcept, CodeableReference, Coding, ContactPoint, Count, Distance, Duration, HumanName, Identifier, Money, Period, Quantity, Range, Ratio, RatioRange, Reference, SampledData, Signature, Timing, ContactDetail, DataRequirement, Expression, ParameterDefinition, RelatedArtifact, TriggerDefinition, UsageContext, Availability, ExtendedContactDetail, Dosage, Meta
[x] Note	See Choice of Data Types for further information about how to use [x]
Summary	false
Invariants	Defined on this element ele-1: All FHIR elements must have a @value or children (: hasValue() or (children().count() > id.count()))