# text.div
Ncts_complete_code_system

URL

https://healthterminologies.gov.au/fhir/StructureDefinition/complete-code-system-4

Base Definition

http://hl7.org/fhir/StructureDefinition/CodeSystem

Status

ACTIVE

Publisher

Australian Digital Health Agency

Description

This StructureDefinition describes the NCTS Complete Code System, a profile of the FHIR&reg; CodeSystem resource. The NCTS Complete Code System is designed to represent terminologies published as part of the National Clinical Terminology Service, and maximise interoperability within the NCTS ecosystem.

Elements (Snapshot)

Path | Cardinality | Type | Definition
CodeSystem | 1..1 | | A code system resource specifies a set of codes drawn from one or more code systems.
CodeSystem. id | 0..1 | id | The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.
CodeSystem. meta | 0..1 | Meta | The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content might not always be associated with version changes to the resource.
CodeSystem. implicitRules | 0..0 | uri | A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content.
CodeSystem. language | 0..1 | code | The base language in which the resource is written.
CodeSystem. text | 1..1 | Narrative | A human-readable narrative that contains a summary of the resource, and may be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety.
CodeSystem. contained | 0..0 | Resource | These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, and nor can they have their own independent transaction scope.
CodeSystem. extension | 0..* | Extension | May be used to represent additional information that is not part of the basic definition of the resource. 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.
CodeSystem. modifierExtension | 0..0 | Extension | May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.
CodeSystem. url | 1..1 | uri | An absolute URI that is used to identify this code system when it is referenced in a specification, model, design or an instance. This SHALL be a URL, SHOULD be globally unique, and SHOULD be an address at which this code system is (or will be) published. The URL SHOULD include the major version of the code system. For more information see [Technical and Business Versions](resource.html#versions). This is used in [Coding]{datatypes.html#Coding}.system.
CodeSystem. identifier | 1..* | Identifier | A formal identifier that is used to identify this code system when it is represented in other formats, or referenced in a specification, model, design or an instance.
CodeSystem. identifier. id | 0..1 | string | Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
CodeSystem. identifier. extension | 0..* | 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.
CodeSystem. identifier. use | 0..1 | code | The purpose of this identifier.
CodeSystem. identifier. type | 0..1 | CodeableConcept | A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.
CodeSystem. identifier. system | 1..1 | uri | Establishes the namespace for the value - that is, a URL that describes a set values that are unique.
CodeSystem. identifier. value | 1..1 | string | The portion of the identifier typically relevant to the user and which is unique within the context of the system.
CodeSystem. identifier. period | 0..1 | Period | Time period during which identifier is/was valid for use.
CodeSystem. identifier. assigner | 0..1 | Reference | Organization that issued/manages the identifier.
CodeSystem. version | 1..1 | string | The identifier that is used to identify this version of the code system when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the code system author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence. This is used in [Coding]{datatypes.html#Coding}.version.
CodeSystem. name | 1..1 | string | A natural language name identifying the code system. This name should be usable as an identifier for the module by machine processing applications such as code generation.
CodeSystem. title | 1..1 | string | A short, descriptive, user-friendly title for the code system.
CodeSystem. status | 1..1 | code | The date (and optionally time) when the code system resource was created or revised.
CodeSystem. experimental | 1..1 | boolean | A boolean value to indicate that this code system is authored for testing purposes (or education/evaluation/marketing), and is not intended to be used for genuine usage.
CodeSystem. date | 1..1 | dateTime | The date (and optionally time) when the code system was published. The date must change if and when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the code system changes.
CodeSystem. publisher | 1..1 | string | The name of the individual or organization that published the code system.
CodeSystem. contact | 0..* | ContactDetail | Contact details to assist a user in finding and communicating with the publisher.
CodeSystem. contact. id | 0..1 | string | Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
CodeSystem. contact. extension | 0..* | 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.
CodeSystem. contact. name | 0..1 | string | The name of an individual to contact.
CodeSystem. contact. telecom | 1..* | ContactPoint | The contact details for the individual (if a name was provided) or the organization.
CodeSystem. description | 1..1 | markdown | A free text natural language description of the code system from a consumer's perspective.
CodeSystem. useContext | 0..* | UsageContext | The content was developed with a focus and intent of supporting the contexts that are listed. These contexts may be general categories (gender, age, ...) or may be references to specific programs (insurance plans, studies, ...) and may be used to assist with indexing and searching for appropriate code system instances.
CodeSystem. jurisdiction | 0..* | CodeableConcept | A legal or geographic region in which the code system is intended to be used.
CodeSystem. purpose | 0..1 | markdown | Explanation of why this code system is needed and why it has been designed as it has.
CodeSystem. copyright | 1..1 | markdown | A copyright statement relating to the code system and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the code system.
CodeSystem. caseSensitive | 1..1 | boolean | If code comparison is case sensitive when codes within this system are compared to each other.
CodeSystem. valueSet | 0..1 | canonical | Canonical reference to the value set that contains the entire code system.
CodeSystem. hierarchyMeaning | 0..1 | code | The meaning of the hierarchy of concepts as represented in this resource.
CodeSystem. compositional | 1..1 | boolean | True If code system defines a post-composition grammar.
CodeSystem. versionNeeded | 1..1 | boolean | This flag is used to signify that the code system has not (or does not) maintain the definitions, and a version must be specified when referencing this code system.
CodeSystem. content | 1..1 | code | How much of the content of the code system - the concepts and codes it defines - are represented in this resource.
CodeSystem. supplements | 0..0 | canonical | The canonical URL of the code system that this code system supplement is adding designations and properties to.
CodeSystem. count | 1..1 | unsignedInt | The total number of concepts defined by the code system. Where the code system has a compositional grammar, the count refers to the number of base (primitive) concepts.
CodeSystem. filter | 0..* | BackboneElement | A filter that can be used in a value set compose statement when selecting concepts using a filter.
CodeSystem. filter. id | 0..1 | string | Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
CodeSystem. filter. extension | 0..* | 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.
CodeSystem. filter. modifierExtension | 0..0 | Extension | May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.
CodeSystem. filter. code | 1..1 | code | The code that identifies this filter when it is used as a filter in [ValueSet](http://hl7.org/fhir/R4/valueset.html#).compose.include.filter.
CodeSystem. filter. description | 0..1 | string | A description of how or why the filter is used.
CodeSystem. filter. operator | 1..* | code | A list of operators that can be used with the filter.
CodeSystem. filter. value | 1..1 | string | A description of what the value for the filter should be.
CodeSystem. property | 0..* | BackboneElement | A property defines an additional slot through which additional information can be provided about a concept.
CodeSystem. property. id | 0..1 | string | Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
CodeSystem. property. extension | 0..* | 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.
CodeSystem. property. modifierExtension | 0..0 | Extension | May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.
CodeSystem. property. code | 1..1 | code | A code that is used to identify the property. The code is used internally (in CodeSystem.concept.property.code) and also externally, such as in property filters.
CodeSystem. property. uri | 0..1 | uri | Reference to the formal meaning of the property. One possible source of meaning is the [Concept Properties](http://hl7.org/fhir/R4/codesystem-concept-properties.html) code system.
CodeSystem. property. description | 0..1 | string | A description of the property- why it is defined, and how its value might be used.
CodeSystem. property. type | 1..1 | code | The type of the property value. Properties of type "code" contain a code defined by the code system (e.g. a reference to another defined concept).
CodeSystem. concept | 1..* | BackboneElement | Concepts that are in the code system. The concept definitions are inherently hierarchical, but the definitions must be consulted to determine what the meaning of the hierarchical relationships are.
CodeSystem. concept. id | 0..1 | string | Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
CodeSystem. concept. extension | 0..* | 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.
CodeSystem. concept. modifierExtension | 0..0 | Extension | May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.
CodeSystem. concept. code | 1..1 | code | A code - a text symbol - that uniquely identifies the concept within the code system.
CodeSystem. concept. display | 1..1 | string | A human readable string that is the recommended default way to present this concept to a user.
CodeSystem. concept. definition | 1..1 | string | The formal definition of the concept. The code system resource does not make formal definitions required, because of the prevalence of legacy systems. However, they are highly recommended, as without them there is no formal meaning associated with the concept.
CodeSystem. concept. designation | 0..* | BackboneElement | Additional representations for the concept - other languages, aliases, specialized purposes, used for particular purposes, etc.
CodeSystem. concept. designation. id | 0..1 | string | Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
CodeSystem. concept. designation. extension | 0..* | 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.
CodeSystem. concept. designation. modifierExtension | 0..0 | Extension | May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.
CodeSystem. concept. designation. language | 0..1 | code | The language this designation is defined for.
CodeSystem. concept. designation. use | 1..1 | Coding | A code that details how this designation would be used.
CodeSystem. concept. designation. value | 1..1 | string | The text value for this designation.
CodeSystem. concept. property | 0..* | BackboneElement | A property value for this concept.
CodeSystem. concept. property. id | 0..1 | string | Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
CodeSystem. concept. property. extension | 0..* | 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.
CodeSystem. concept. property. modifierExtension | 0..0 | Extension | May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.
CodeSystem. concept. property. code | 1..1 | code | A code that is a reference to CodeSystem.property.code.
CodeSystem. concept. property. value[x] | 1..1 | [ code | Coding | string | integer | boolean | dateTime | decimal ] | The value of this property.
CodeSystem. concept. concept | 0..* | see CodeSystem.concept | Defines children of a concept to produce a hierarchy of concepts. The nature of the relationships is variable (is-a/contains/categorizes) - see hierarchyMeaning.

# description
This StructureDefinition describes the NCTS Complete Code System, a profile of the FHIR® CodeSystem resource. The NCTS Complete Code System is designed to represent terminologies published as part of the National Clinical Terminology Service, and maximise interoperability within the NCTS ecosystem.

# purpose
The purpose of this profile is to codify a set of general best practices with respect to representing code systems in FHIR, and an opinionated approach to versioning that is compatible with the syndication model that NCTS uses.

# snapshot.element[].short
Declares the existence of and describes a code system or code system supplement

# snapshot.element[].definition
A code system resource specifies a set of codes drawn from one or more code systems.

# snapshot.element[].constraint[].human
Name should be usable as an identifier for the module by machine processing applications such as code generation

# snapshot.element[].constraint[].human
Within a code system definition, all the codes SHALL be unique

# snapshot.element[].constraint[].human
If the resource is contained in another resource, it SHALL NOT contain nested Resources

# snapshot.element[].constraint[].human
If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource

# snapshot.element[].constraint[].human
If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated

# snapshot.element[].constraint[].human
If a resource is contained in another resource, it SHALL NOT have a security label

# snapshot.element[].constraint[].extension[].valueMarkdown
When a resource has no narrative, only systems that fully understand the data can display the resource to a human safely. Including a human readable representation in the resource makes for a much more robust eco-system and cheaper handling of resources by intermediary systems. Some ecosystems restrict distribution of resources to only those systems that do fully understand the resources, and as a consequence implementers may believe that the narrative is superfluous. However experience shows that such eco-systems often open up to new participants over time.

# snapshot.element[].constraint[].human
A resource should have narrative for robust management

# snapshot.element[].definition
The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.

# snapshot.element[].comment
The only time that a resource does not have an id is when it is being submitted to the server using a create operation.

# snapshot.element[].definition
The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content might not always be associated with version changes to the resource.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
A set of rules under which this content was created

# snapshot.element[].definition
A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content.

# snapshot.element[].comment
Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of it's narrative along with other profiles, value sets, etc.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].isModifierReason
This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation

# snapshot.element[].definition
The base language in which the resource is written.

# snapshot.element[].comment
Language is provided to support indexing and accessibility (typically, services such as text to speech use the language tag). The html language tag in the narrative applies  to the narrative. The language tag on the resource may be used to specify the language of other presentations generated from the data in the resource. Not all the content has to be in the base language. The Resource.language should not be assumed to apply to the narrative automatically. If a language is specified, it should it also be specified on the div element in the html (see rules in HTML5 for information about the relationship between xml:lang and the html lang attribute).

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Text summary of the resource, for human interpretation

# snapshot.element[].definition
A human-readable narrative that contains a summary of the resource, and may be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety.

# snapshot.element[].comment
Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied).  This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, and nor can they have their own independent transaction scope.

# snapshot.element[].comment
This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags In their meta elements, but SHALL NOT have security labels.

# snapshot.element[].short
Additional content defined by implementations

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the resource. 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.

# snapshot.element[].comment
There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].isModifierReason
Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them

# snapshot.element[].short
Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system)

# snapshot.element[].definition
An absolute URI that is used to identify this code system when it is referenced in a specification, model, design or an instance. This SHALL be a URL, SHOULD be globally unique, and SHOULD be an address at which this code system is (or will be) published. The URL SHOULD include the major version of the code system. For more information see [Technical and Business Versions](resource.html#versions). This is used in [Coding]{datatypes.html#Coding}.system.

# snapshot.element[].comment
Can be a urn:uuid: or a urn:oid: but real http: addresses are preferred.  Multiple instances may share the same URL if they have a distinct version.

The determination of when to create a new version of a resource (same url, new version) vs. defining a new artifact is up to the author.  Considerations for making this decision are found in [Technical and Business Versions](http://hl7.org/fhir/R4/resource.html#versions). 

In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the [meta.source](http://hl7.org/fhir/R4/resource.html#meta) element to indicate where the current master source of the resource can be found.

# snapshot.element[].requirements
Allows the code system to be referenced by a single globally unique identifier.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Additional identifier for the code system (business identifier)

# snapshot.element[].definition
A formal identifier that is used to identify this code system when it is represented in other formats, or referenced in a specification, model, design or an instance.

# snapshot.element[].comment
Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, and can then identify this code system outside of FHIR, where it is not possible to use the logical URI.  Note that HL7 defines at least three identifiers for many of its code systems - the FHIR canonical URL, the OID and the V2 Table 0396 mnemonic code.

# snapshot.element[].requirements
Allows externally provided and/or usable business identifiers to be easily associated with the module.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

# snapshot.element[].slicing.description
Extensions are always sliced by (at least) url

# snapshot.element[].short
Additional content defined by implementations

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and 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.

# snapshot.element[].comment
There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].short
usual | official | temp | secondary | old (If known)

# snapshot.element[].comment
Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

# snapshot.element[].requirements
Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].isModifierReason
This is labeled as "Is Modifier" because applications should not mistake a temporary id for a permanent one.

# snapshot.element[].binding.description
Identifies the purpose for this identifier, if known .

# snapshot.element[].definition
A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.

# snapshot.element[].comment
This element deals only with general categories of identifiers.  It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage.   Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.

# snapshot.element[].requirements
Allows users to make use of identifiers when the identifier system is not known.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].binding.description
A coded type for an identifier that can be used to determine which identifier to use for a specific purpose.

# snapshot.element[].definition
Establishes the namespace for the value - that is, a URL that describes a set values that are unique.

# snapshot.element[].comment
Identifier.system is always case sensitive.

# snapshot.element[].requirements
There are many sets  of identifiers.  To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
The portion of the identifier typically relevant to the user and which is unique within the context of the system.

# snapshot.element[].comment
If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986.  The value's primary purpose is computational mapping.  As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.)  A value formatted for human display can be conveyed using the [Rendered Value extension](http://hl7.org/fhir/R4/extension-rendered-value.html). Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processer to be confident that non-case-sensitive processing is safe.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].mapping[].map
II.extension or II.root if system indicates OID or GUID (Or Role.id.extension or root)

# snapshot.element[].short
Time period when id is/was valid for use

# snapshot.element[].definition
Time period during which identifier is/was valid for use.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].mapping[].map
Role.effectiveTime or implied by context

# snapshot.element[].short
Organization that issued id (may be just text)

# snapshot.element[].definition
Organization that issued/manages the identifier.

# snapshot.element[].comment
The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].mapping[].map
II.assigningAuthorityName but note that this is an improper use by the definition of the field.  Also Role.scoper

# snapshot.element[].short
Business version of the code system (Coding.version)

# snapshot.element[].definition
The identifier that is used to identify this version of the code system when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the code system author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence. This is used in [Coding]{datatypes.html#Coding}.version.

# snapshot.element[].comment
There may be different code system instances that have the same identifier but different versions.  The version can be appended to the url in a reference to allow a reference to a particular business version of the code system with the format [url]|[version].

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Name for this code system (computer friendly)

# snapshot.element[].definition
A natural language name identifying the code system. This name should be usable as an identifier for the module by machine processing applications such as code generation.

# snapshot.element[].comment
The name is not expected to be globally unique. The name should be a simple alphanumeric type name to ensure that it is machine-processing friendly.

# snapshot.element[].requirements
Support human navigation and code generation.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Name for this code system (human friendly)

# snapshot.element[].definition
A short, descriptive, user-friendly title for the code system.

# snapshot.element[].comment
This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
The date (and optionally time) when the code system resource was created or revised.

# snapshot.element[].comment
Allows filtering of code systems that are appropriate for use versus not.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].isModifierReason
This is labeled as "Is Modifier" because applications should not use a retired {{title}} without due consideration

# snapshot.element[].definition
A boolean value to indicate that this code system is authored for testing purposes (or education/evaluation/marketing), and is not intended to be used for genuine usage.

# snapshot.element[].comment
Allows filtering of code systems that are appropriate for use versus not.

# snapshot.element[].requirements
Enables experimental content to be developed following the same lifecycle that would be used for a production-level code system.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
The date  (and optionally time) when the code system was published. The date must change if and when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the code system changes.

# snapshot.element[].comment
Note that this is not the same as the resource last-modified-date, since the resource may be a secondary representation of the code system. Additional specific dates may be added as extensions or be found by consulting Provenances associated with past versions of the resource.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Name of the publisher (organization or individual)

# snapshot.element[].definition
The name of the individual or organization that published the code system.

# snapshot.element[].comment
Usually an organization but may be an individual. The publisher (or steward) of the code system is the organization or individual primarily responsible for the maintenance and upkeep of the code system. This is not necessarily the same individual or organization that developed and initially authored the content. The publisher is the primary point of contact for questions or issues with the code system. This item SHOULD be populated unless the information is available from context.

# snapshot.element[].requirements
Helps establish the "authority/credibility" of the code system.  May also allow for contact.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Contact details to assist a user in finding and communicating with the publisher.

# snapshot.element[].comment
May be a web site, an email address, a telephone number, etc.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

# snapshot.element[].slicing.description
Extensions are always sliced by (at least) url

# snapshot.element[].short
Additional content defined by implementations

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and 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.

# snapshot.element[].comment
There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].comment
If there is no named individual, the telecom information is for the organization as a whole.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Contact details for individual or organization

# snapshot.element[].definition
The contact details for the individual (if a name was provided) or the organization.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Natural language description of the code system

# snapshot.element[].definition
A free text natural language description of the code system from a consumer's perspective.

# snapshot.element[].comment
This description can be used to capture details such as why the code system was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the code system as conveyed in the 'text' field of the resource itself. This item SHOULD be populated unless the information is available from context (e.g. the language of the code system is presumed to be the predominant language in the place the code system was created).

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
The context that the content is intended to support

# snapshot.element[].definition
The content was developed with a focus and intent of supporting the contexts that are listed. These contexts may be general categories (gender, age, ...) or may be references to specific programs (insurance plans, studies, ...) and may be used to assist with indexing and searching for appropriate code system instances.

# snapshot.element[].comment
When multiple useContexts are specified, there is no expectation that all or any of the contexts apply.

# snapshot.element[].requirements
Assist in searching for appropriate content.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Intended jurisdiction for code system (if applicable)

# snapshot.element[].definition
A legal or geographic region in which the code system is intended to be used.

# snapshot.element[].comment
It may be possible for the code system to be used in jurisdictions other than those for which it was originally designed or intended.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].binding.description
Countries and regions within which this artifact is targeted for use.

# snapshot.element[].definition
Explanation of why this code system is needed and why it has been designed as it has.

# snapshot.element[].comment
This element does not describe the usage of the code system. Instead, it provides traceability of ''why'' the resource is either needed or ''why'' it is defined as it is.  This may be used to point to source materials or specifications that drove the structure of this code system.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
A copyright statement relating to the code system and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the code system.

# snapshot.element[].comment
... Sometimes, the copyright differs between the code system and the codes that are included. The copyright statement should clearly differentiate between these when required.

# snapshot.element[].requirements
Consumers must be able to determine any legal restrictions on the use of the code system and/or its content.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
If code comparison is case sensitive when codes within this system are compared to each other.

# snapshot.element[].comment
If this value is missing, then it is not specified whether a code system is case sensitive or not. When the rule is not known, Postel's law should be followed: produce codes with the correct case, and accept codes in any case. This element is primarily provided to support validation software.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Canonical reference to the value set with entire code system

# snapshot.element[].definition
Canonical reference to the value set that contains the entire code system.

# snapshot.element[].comment
The definition of the value set SHALL include all codes from this code system and only codes from this code system, and it SHALL be immutable.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
grouped-by | is-a | part-of | classified-with

# snapshot.element[].definition
The meaning of the hierarchy of concepts as represented in this resource.

# snapshot.element[].comment
Note that other representations might have a different hierarchy or none at all, and represent the information using properties.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].binding.description
The meaning of the hierarchy of concepts in a code system.

# snapshot.element[].short
If code system defines a compositional grammar

# snapshot.element[].definition
True If code system defines a post-composition grammar.

# snapshot.element[].comment
Note that the code system resource does not define what the compositional grammar is, only whether or not there is one.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
This flag is used to signify that the code system has not (or does not) maintain the definitions, and a version must be specified when referencing this code system.

# snapshot.element[].comment
Best practice is that code systems do not redefine concepts, or that if concepts are redefined, a new code system definition is created. But this is not always possible, so some code systems may be defined as 'versionNeeded'.

Most code systems occasionally refine the displays defined for concepts between versions. Contexts in which the concept display values are validated may require that the version be specified for some code systems irrespective of the value of this property.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
not-present | example | fragment | complete | supplement

# snapshot.element[].definition
How much of the content of the code system - the concepts and codes it defines - are represented in this resource.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].binding.description
The extent of the content of the code system (the concepts and codes it defines) are represented in a code system resource.

# snapshot.element[].short
Canonical URL of Code System this adds designations and properties to

# snapshot.element[].definition
The canonical URL of the code system that this code system supplement is adding designations and properties to.

# snapshot.element[].comment
The most common use of a code system supplement is to add additional language support. Supplements do not make sense in terms of the NCTS Complete Code System profile which is used to define CodeSystems in their entirety.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
The total number of concepts defined by the code system. Where the code system has a compositional grammar, the count refers to the number of base (primitive) concepts.

# snapshot.element[].comment
The count of concepts defined in this resource cannot be more than this value but may be less for several reasons - see the content element.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
A filter that can be used in a value set compose statement when selecting concepts using a filter.

# snapshot.element[].comment
Note that filters defined in code systems usually require custom code on the part of any terminology engine that will make them available for use in value set filters. For this reason, they are generally only seen in high value published terminologies.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

# snapshot.element[].short
Additional content defined by implementations

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and 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.

# snapshot.element[].comment
There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].isModifierReason
Modifier extensions are expected to modify the meaning or interpretation of the element that contains them

# snapshot.element[].definition
The code that identifies this filter when it is used as a filter in [ValueSet](http://hl7.org/fhir/R4/valueset.html#).compose.include.filter.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
A description of how or why the filter is used.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
= | is-a | descendent-of | is-not-a | regex | in | not-in | generalizes | exists

# snapshot.element[].definition
A list of operators that can be used with the filter.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].binding.description
The kind of operation to perform as a part of a property based filter.

# snapshot.element[].definition
A description of what the value for the filter should be.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Additional information supplied about each concept

# snapshot.element[].definition
A property defines an additional slot through which additional information can be provided about a concept.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

# snapshot.element[].short
Additional content defined by implementations

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and 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.

# snapshot.element[].comment
There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].isModifierReason
Modifier extensions are expected to modify the meaning or interpretation of the element that contains them

# snapshot.element[].short
Identifies the property on the concepts, and when referred to in operations

# snapshot.element[].definition
A code that is used to identify the property. The code is used internally (in CodeSystem.concept.property.code) and also externally, such as in property filters.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Reference to the formal meaning of the property. One possible source of meaning is the [Concept Properties](http://hl7.org/fhir/R4/codesystem-concept-properties.html) code system.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Why the property is defined, and/or what it conveys

# snapshot.element[].definition
A description of the property- why it is defined, and how its value might be used.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
code | Coding | string | integer | boolean | dateTime | decimal

# snapshot.element[].definition
The type of the property value. Properties of type "code" contain a code defined by the code system (e.g. a reference to another defined concept).

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Concepts that are in the code system. The concept definitions are inherently hierarchical, but the definitions must be consulted to determine what the meaning of the hierarchical relationships are.

# snapshot.element[].comment
If this is empty, it means that the code system resource does not represent the content of the code system.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

# snapshot.element[].short
Additional content defined by implementations

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and 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.

# snapshot.element[].comment
There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].isModifierReason
Modifier extensions are expected to modify the meaning or interpretation of the element that contains them

# snapshot.element[].definition
A code - a text symbol - that uniquely identifies the concept within the code system.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
A human readable string that is the recommended default way to present this concept to a user.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
The formal definition of the concept. The code system resource does not make formal definitions required, because of the prevalence of legacy systems. However, they are highly recommended, as without them there is no formal meaning associated with the concept.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Additional representations for the concept

# snapshot.element[].definition
Additional representations for the concept - other languages, aliases, specialized purposes, used for particular purposes, etc.

# snapshot.element[].comment
Concepts have both a ```display``` and an array of ```designation```. The display is equivalent to a special designation with an implied ```designation.use``` of "primary code" and a language equal to the [Resource Language](http://hl7.org/fhir/R4/resource.html#language).

# snapshot.element[].requirements
Many concept definition systems support multiple representations, in multiple languages, and for multiple purposes.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

# snapshot.element[].short
Additional content defined by implementations

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and 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.

# snapshot.element[].comment
There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].isModifierReason
Modifier extensions are expected to modify the meaning or interpretation of the element that contains them

# snapshot.element[].definition
The language this designation is defined for.

# snapshot.element[].comment
In the absence of a language, the resource language applies.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].short
Details how this designation would be used

# snapshot.element[].definition
A code that details how this designation would be used.

# snapshot.element[].comment
If no use is provided, the designation can be assumed to be suitable for general display to a human user.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].binding.description
Details of how a designation would be used.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

# snapshot.element[].short
Additional content defined by implementations

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and 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.

# snapshot.element[].comment
There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions.  The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
Must have either extensions or value[x], not both

# snapshot.element[].isModifierReason
Modifier extensions are expected to modify the meaning or interpretation of the element that contains them

# snapshot.element[].definition
A code that is a reference to CodeSystem.property.code.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# snapshot.element[].definition
Defines children of a concept to produce a hierarchy of concepts. The nature of the relationships is variable (is-a/contains/categorizes) - see hierarchyMeaning.

# snapshot.element[].constraint[].human
All FHIR elements must have a @value or children

# snapshot.element[].constraint[].expression
hasValue() or (children().count() > id.count())

# differential.element[].definition
A code system resource specifies a set of codes drawn from one or more code systems.

# differential.element[].definition
A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content.

# differential.element[].definition
A human-readable narrative that contains a summary of the resource, and may be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety.

# differential.element[].definition
These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, and nor can they have their own independent transaction scope.

# differential.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# differential.element[].definition
An absolute URI that is used to identify this code system when it is referenced in a specification, model, design or an instance. This SHALL be a URL, SHOULD be globally unique, and SHOULD be an address at which this code system is (or will be) published. The URL SHOULD include the major version of the code system. For more information see [Technical and Business Versions](resource.html#versions). This is used in [Coding]{datatypes.html#Coding}.system.

# differential.element[].definition
A formal identifier that is used to identify this code system when it is represented in other formats, or referenced in a specification, model, design or an instance.

# differential.element[].definition
Establishes the namespace for the value - that is, a URL that describes a set values that are unique.

# differential.element[].definition
The portion of the identifier typically relevant to the user and which is unique within the context of the system.

# differential.element[].definition
The identifier that is used to identify this version of the code system when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the code system author and is not expected to be globally unique. For example, it might be a timestamp (e.g. yyyymmdd) if a managed version is not available. There is also no expectation that versions can be placed in a lexicographical sequence. This is used in [Coding]{datatypes.html#Coding}.version.

# differential.element[].definition
A natural language name identifying the code system. This name should be usable as an identifier for the module by machine processing applications such as code generation.

# differential.element[].definition
A short, descriptive, user-friendly title for the code system.

# differential.element[].definition
A boolean value to indicate that this code system is authored for testing purposes (or education/evaluation/marketing), and is not intended to be used for genuine usage.

# differential.element[].definition
The date  (and optionally time) when the code system was published. The date must change if and when the business version changes and it must change if the status code changes. In addition, it should change when the substantive content of the code system changes.

# differential.element[].definition
The name of the individual or organization that published the code system.

# differential.element[].definition
The contact details for the individual (if a name was provided) or the organization.

# differential.element[].definition
A free text natural language description of the code system from a consumer's perspective.

# differential.element[].definition
A copyright statement relating to the code system and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the code system.

# differential.element[].definition
If code comparison is case sensitive when codes within this system are compared to each other.

# differential.element[].definition
True If code system defines a post-composition grammar.

# differential.element[].definition
This flag is used to signify that the code system has not (or does not) maintain the definitions, and a version must be specified when referencing this code system.

# differential.element[].definition
How much of the content of the code system - the concepts and codes it defines - are represented in this resource.

# differential.element[].definition
The canonical URL of the code system that this code system supplement is adding designations and properties to.

# differential.element[].comment
The most common use of a code system supplement is to add additional language support. Supplements do not make sense in terms of the NCTS Complete Code System profile which is used to define CodeSystems in their entirety.

# differential.element[].definition
The total number of concepts defined by the code system. Where the code system has a compositional grammar, the count refers to the number of base (primitive) concepts.

# differential.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# differential.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# differential.element[].definition
Concepts that are in the code system. The concept definitions are inherently hierarchical, but the definitions must be consulted to determine what the meaning of the hierarchical relationships are.

# differential.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# differential.element[].definition
A human readable string that is the recommended default way to present this concept to a user.

# differential.element[].definition
The formal definition of the concept. The code system resource does not make formal definitions required, because of the prevalence of legacy systems. However, they are highly recommended, as without them there is no formal meaning associated with the concept.

# differential.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

# differential.element[].definition
A code that details how this designation would be used.

# differential.element[].definition
May be used to represent additional information that is not part of the basic definition of the element, and that modifies the understanding of the element that contains it. Usually modifier elements provide negation or qualification. In order 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 is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.