A code system The CodeSystem resource specifies a set is used to declare the existence of codes drawn from one and describe a code system or more code systems. system supplement and its key properties, and optionally define a part or all of its content.

An absolute URI that is used to identify this code system when it is referenced in a specification, model, design or an instance. instance; also called its canonical identifier. This SHALL be a URL, SHOULD be globally unique, unique and SHOULD be an a literal address at which at which an authoritative instance of this code system is (or will be) published. The This URL SHOULD include can be the major version target of a canonical reference. It SHALL remain the same when the code system. For more information see Technical and Business Versions . system is stored on different servers. This is used in [Coding]{datatypes.html#Coding}.system. Coding .system.

Allows the code system to be referenced by a single globally unique identifier.

Can be a urn:uuid: or a urn:oid:, urn:oid: but real http: addresses are preferred. Multiple instances may share the same url 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 .

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 element to indicate where the current master source of the resource can be found.

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.

Allows externally provided and/or usable business identifiers to be easily associated with the module.

Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier) data type, e.g., to 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.

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. Coding .version.

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 refrence reference to a particular business version of the code system with the format [url]|[version].

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.

Support human navigation and code generation.

The name is not expected to be globally unique. The name should be a simple alpha-numeric alphanumeric type name to ensure that it is computable machine-processing friendly.

A short, descriptive, user-friendly title for the code system.

This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc.

The status of this code system. Enables tracking the life-cycle of date (and optionally time) when the content. code system resource was created or revised.

Allows filtering of code systems that are appropriate for use vs. versus not. This is labeled as "Is Modifier" because applications should not use a retired code system without due consideration.

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

Enables experimental content to be developed following the same lifecycle that would be used for a production-level code system.

Allows filtering of code system systems that are appropriate for use vs. versus not. This is labeled as "Is Modifier" because applications should not use an experimental code system in production.

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.

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.

The name of the individual or organization or individual that published the code system.

Helps establish the "authority/credibility" "authority/credibility" of the code system. May also allow for contact.

Usually an organization, 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.

Contact details to assist a user in finding and communicating with the publisher.

May be a web site, an email address, a telephone number, etc.

A free text natural language description of the code system from a consumer's perspective.

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 profile code system is presumed to be the predominant language in the place the profile code system was created).

The content was developed with a focus and intent of supporting the contexts that are listed. These terms 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.

Assist in searching for appropriate content.

When multiple useContexts are specified, there is no expectation whether that all or any of the contexts apply.

A legal or geographic region in which the code system is intended to be used.

It may be possible for the code system to be used in jurisdictions other than those for which it was originally designed or intended.

Explaination Explanation of why this code system is needed and why it has been designed as it has.

This element does not describe the usage of the code system Instead 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.

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.

Consumers must be able to determine any legal restrictions on the use of the code system and/or its content.

... Sometimes, the copyright differs between the code system and the codes that are included. The copyright statement should clearly differentiate between these when required.

If code comparison is case sensitive when codes within this system are compared to each other.

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.

Canonical URL of reference to the value set that contains the entire code system.

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.

The meaning of the hierarchy of concepts. concepts as represented in this resource.

Note that other representations might have a different hierarchy or none at all, and represent the information using properties.

True If The code system defines a post-composition compositional (post-coordination) grammar.

Note that the code system resource does not define what the compositional grammar is, only whether or not there is one.

This flag is used to signify that the code system has not (or does not) maintain the definitions, and not commit to concept permanence across versions. If true, a version must be specified when referencing this code system.

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.

How much The extent of the content of the code system - the (the concepts and codes it defines - defines) are represented in this resource. resource instance.

The canonical URL of the code system that this code system supplement is adding designations and properties to.

The most common use of a code system supplement is to add additional language support.

The total number of concepts defined by the code system. Where the code system has a compositional grammar, the basis of this count refers to is defined by the number of base (primitive) concepts. system steward.

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

A filter that can be used in a value set compose statement when selecting concepts using a filter.

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.

The code that identifies this filter when it is used as a filter in the instance. ValueSet .compose.include.filter.

A description of how or why the filter is used.

A list of operators that can be used with the filter.

A description of what the value for the filter should be.

A property defines an additional slot through which additional information can be provided about a concept.

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.

Reference to the formal meaning of the property. One possible source of meaning is the Concept Properties code system.

A description of the property- why it is defined, and how its value might be used.

The type of the property value. Properties of type "code" "code" contain a code defined by the code system (e.g. a reference to anotherr another defined concept).

Concepts that are in the code system. The concept definitions are inherently hierarchical, but the definitions must be consulted to determine what the meaning meanings of the hierarchical relationships are.

If this is empty, it means that the code system resource does not represent the content of the code system.

A code - a text symbol - that uniquely identifies the concept within the code system.

A human readable string that is the recommended default way to present this concept to a user.

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.

Additional representations for the concept - other languages, aliases, specialized purposes, used for particular purposes, etc.

Many concept definition systems support multiple representations, in multiple languages, and for multiple purposes.

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 .

The language this designation is defined for.

In the absence of a language, the resource language applies.

A code that details how this designation would be used.

If no use is provided, the designation can be assumed to be suitable for general display to a human user.

The text value for this designation.

A property value for this concept.

A code that is a reference to CodeSystem.property.code.

The value of this property.

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