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StructureDefinition: ShareableNamingSystem - XML

Terminology Infrastructure Work Group
Maturity Level: 0
Trial Use
Use Context: Any
ShareableNamingSystem
<?xml version="1.0" encoding="UTF-8"?>

<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="shareablenamingsystem"/> 
  <text> 
    <status value="generated"/> 
    <div xmlns="http://www.w3.org/1999/xhtml">to do</div> 
  </text> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="1"/> 
  </extension> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
    <valueCode value="vocab"/> 
  </extension> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
    <valueCode value="trial-use"/> 
  </extension> 
  <url value="http://hl7.org/fhir/StructureDefinition/shareablenamingsystem"/> 
  <identifier> 
    <system value="urn:ietf:rfc:3986"/> 
    <value value="urn:oid:2.16.840.1.113883.4.642.5.1260"/> 
  </identifier> 
  <version value="5.0.0"/> 
  <name value="ShareableNamingSystem"/> 
  <title value="Shareable NamingSystem"/> 
  <status value="draft"/> 
  <experimental value="false"/> 
  <date value="2020-12-28T16:55:11+11:00"/> 
  <publisher value="HL7"/> 
  <description value="Enforces the minimum information set for the naming system metadata required by
   HL7 and other organizations that share and publish naming systems"/> 
  <fhirVersion value="5.0.0"/> 
  <mapping> 
    <identity value="rim"/> 
    <uri value="http://hl7.org/v3"/> 
    <name value="RIM Mapping"/> 
  </mapping> 
  <mapping> 
    <identity value="workflow"/> 
    <uri value="http://hl7.org/fhir/workflow"/> 
    <name value="Workflow Pattern"/> 
  </mapping> 
  <mapping> 
    <identity value="w5"/> 
    <uri value="http://hl7.org/fhir/fivews"/> 
    <name value="FiveWs Pattern Mapping"/> 
  </mapping> 
  <mapping> 
    <identity value="objimpl"/> 
    <uri value="http://hl7.org/fhir/object-implementation"/> 
    <name value="Object Implementation Information"/> 
  </mapping> 
  <mapping> 
    <identity value="v2"/> 
    <uri value="http://hl7.org/v2"/> 
    <name value="HL7 V2 Mapping"/> 
  </mapping> 
  <kind value="resource"/> 
  <abstract value="false"/> 
  <type value="NamingSystem"/> 
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/NamingSystem"/> 
  <derivation value="constraint"/> 
  <snapshot> 
    <element id="NamingSystem">
      <path value="NamingSystem"/> 
      <short value="System of unique identification"/> 
      <definition value="A curated namespace that issues unique symbols within that namespace for the identification
       of concepts, people, devices, etc.  Represents a &quot;System&quot; used within
       the Identifier and Coding data types."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <constraint> 
        <key value="cnl-0"/> 
        <severity value="warning"/> 
        <human value="Name should be usable as an identifier for the module by machine processing applications
         such as code generation"/> 
        <expression value="name.exists() implies name.matches('^[A-Z]([A-Za-z0-9_]){1,254}$')"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/NamingSystem"/> 
      </constraint> 
      <constraint> 
        <key value="nsd-1"/> 
        <severity value="error"/> 
        <human value="Root systems cannot have uuid identifiers"/> 
        <expression value="kind != 'root' or uniqueId.all(type != 'uuid')"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/NamingSystem"/> 
      </constraint> 
      <constraint> 
        <key value="nsd-2"/> 
        <severity value="error"/> 
        <human value="Can't have more than one preferred identifier for a type"/> 
        <expression value="uniqueId.where(preferred = true).select(type).isDistinct()"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/NamingSystem"/> 
      </constraint> 
      <constraint> 
        <key value="nsd-3"/> 
        <severity value="error"/> 
        <human value="Can't have more than one authoritative identifier for a type/period combination
         (only one authoritative identifier allowed at any given point of time)"/> 
        <expression value="uniqueId.where(authoritative = 'true').select(type.toString() &amp; period.start.toString()
         &amp; period.end.toString()).isDistinct()"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/NamingSystem"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="conformance.behavior,conformance.terminology"/> 
      </mapping> 
      <mapping> 
        <identity value="v2"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.id">
      <path value="NamingSystem.id"/> 
      <short value="Logical id of this artifact"/> 
      <definition value="The logical id of the resource, as used in the URL for the resource. Once assigned,
       this value never changes."/> 
      <comment value="Within the context of the FHIR RESTful interactions, the resource has an id except
       for cases like the create and conditional update. Otherwise, the use of the resouce
       id depends on the given use case."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.id"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="id"/> 
        </extension> 
        <code value="http://hl7.org/fhirpath/System.String"/> 
      </type> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.meta">
      <path value="NamingSystem.meta"/> 
      <short value="Metadata about the resource"/> 
      <definition value="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."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.meta"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Meta"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.implicitRules">
      <path value="NamingSystem.implicitRules"/> 
      <short value="A set of rules under which this content was created"/> 
      <definition value="A reference to a set of rules that were followed when the resource was constructed,
       and which must be understood when processing the content. Often, this is a reference
       to an implementation guide that defines the special rules along with other profiles
       etc."/> 
      <comment value="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 its narrative along with other profiles,
       value sets, etc."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.implicitRules"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="uri"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="true"/> 
      <isModifierReason value="This element is labeled as a modifier because the implicit rules may provide additional
       knowledge about the resource that modifies its meaning or interpretation"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.language">
      <path value="NamingSystem.language"/> 
      <short value="Language of the resource content"/> 
      <definition value="The base language in which the resource is written."/> 
      <comment value="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)."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Resource.language"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Language"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/> 
        </extension> 
        <strength value="required"/> 
        <description value="IETF language tag for a human language"/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/all-languages|5.0.0"/> 
        <additional> 
          <purpose value="starter"/> 
          <valueSet value="http://hl7.org/fhir/ValueSet/languages"/> 
        </additional> 
      </binding> 
    </element> 
    <element id="NamingSystem.text">
      <path value="NamingSystem.text"/> 
      <short value="Text summary of the resource, for human interpretation"/> 
      <definition value="A human-readable narrative that contains a summary of the resource and can 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
       &quot;clinically safe&quot; for a human to just read the narrative. Resource definitions
       may define what content should be represented in the narrative to ensure clinical
       safety."/> 
      <comment value="Contained resources do not have a 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 &quot;text blob&quot; or where text is additionally entered raw or narrated
       and encoded information is added later."/> 
      <alias value="narrative"/> 
      <alias value="html"/> 
      <alias value="xhtml"/> 
      <alias value="display"/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="DomainResource.text"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Narrative"/> 
      </type> 
      <condition value="dom-6"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="Act.text?"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.contained">
      <path value="NamingSystem.contained"/> 
      <short value="Contained, inline Resources"/> 
      <definition value="These resources do not have an independent existence apart from the resource that
       contains them - they cannot be identified independently, nor can they have their
       own independent transaction scope. This is allowed to be a Parameters resource
       if and only if it is referenced by a resource that provides context/meaning."/> 
      <comment value="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."/> 
      <alias value="inline resources"/> 
      <alias value="anonymous resources"/> 
      <alias value="contained resources"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="DomainResource.contained"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Resource"/> 
      </type> 
      <condition value="dom-2"/> 
      <condition value="dom-4"/> 
      <condition value="dom-3"/> 
      <condition value="dom-5"/> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.extension">
      <path value="NamingSystem.extension"/> 
      <slicing> 
        <discriminator> 
          <type value="value"/> 
          <path value="url"/> 
        </discriminator> 
        <ordered value="false"/> 
        <rules value="open"/> 
      </slicing> 
      <short value="Extension"/> 
      <definition value="An Extension"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="DomainResource.extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.extension:knowledgeRepresentationLevel">
      <path value="NamingSystem.extension"/> 
      <sliceName value="knowledgeRepresentationLevel"/> 
      <short value="narrative | semi-structured | structured | executable"/> 
      <definition value="Defines a knowledge representation level provided by this knowledge artifact."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="DomainResource.extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
        <profile value="http://hl7.org/fhir/StructureDefinition/cqf-knowledgeRepresentationLevel"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
    </element> 
    <element id="NamingSystem.modifierExtension">
      <path value="NamingSystem.modifierExtension"/> 
      <short value="Extensions that cannot be ignored"/> 
      <definition value="May be used to represent additional information that is not part of the basic definition
       of the resource and that modifies the understanding of the element that contains
       it and/or the understanding of the containing element's descendants. Usually modifier
       elements provide negation or qualification. To make the use of extensions safe
       and managable, there is a strict set of governance applied to the definition and
       use of extensions. Though any implementer 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.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or
       DomainResource (including cannot change the meaning of modifierExtension itself)."/> 
      <comment value="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."/> 
      <requirements value="Modifier extensions allow for extensions that *cannot* be safely ignored to be
       clearly distinguished from the vast majority of extensions which can be safely
       ignored.  This promotes interoperability by eliminating the need for implementers
       to prohibit the presence of extensions. For further information, see the [definition
       of modifier extensions](extensibility.html#modifierExtension)."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="DomainResource.modifierExtension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="true"/> 
      <isModifierReason value="Modifier extensions are expected to modify the meaning or interpretation of the
       resource that contains them"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.url">
      <path value="NamingSystem.url"/> 
      <short value="Canonical identifier for this naming system, represented as a URI (globally unique)"/> 
      <definition value="An absolute URI that is used to identify this naming system when it is referenced
       in a specification, model, design or an instance; also called its canonical identifier.
       This SHOULD be globally unique and SHOULD be a literal address at which an authoritative
       instance of this naming system is (or will be) published. This URL can be the target
       of a canonical reference. It SHALL remain the same when the naming system is stored
       on different servers."/> 
      <comment value="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](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](resource.html#meta)
       element to indicate where the current master source of the resource can be found."/> 
      <requirements value="Allows the naming system to be referenced by a single globally unique identifier."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.url"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="uri"/> 
      </type> 
      <constraint> 
        <key value="cnl-1"/> 
        <severity value="warning"/> 
        <human value="URL should not contain | or # - these characters make processing canonical references
         problematic"/> 
        <expression value="exists() implies matches('^[^|# ]+$')"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/NamingSystem"/> 
      </constraint> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.identifier"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.identifier">
      <path value="NamingSystem.identifier"/> 
      <short value="Additional identifier for the naming system (business identifier)"/> 
      <definition value="A formal identifier that is used to identify this naming system when it is represented
       in other formats, or referenced in a specification, model, design or an instance."/> 
      <comment value="Typically, this is used for identifiers that can go in an HL7 V3 II (instance identifier)
       data type, and can then identify this naming system outside of FHIR, where it is
       not possible to use the logical URI."/> 
      <requirements value="Allows externally provided and/or usable business identifiers to be easily associated
       with the naming system."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.identifier"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Identifier"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.identifier"/> 
      </mapping> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.version">
      <path value="NamingSystem.version"/> 
      <short value="Business version of the naming system"/> 
      <definition value="The identifier that is used to identify this version of the naming system when
       it is referenced in a specification, model, design or instance. This is an arbitrary
       value managed by the naming 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."/> 
      <comment value="There may be different naming 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 naming system with the format
       [url]|[version]. The version SHOULD NOT contain a '#' - see [Business Version](resource.html#
      bv-format)."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.version"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.version"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.versionAlgorithm[x]">
      <path value="NamingSystem.versionAlgorithm[x]"/> 
      <short value="How to compare versions"/> 
      <definition value="Indicates the mechanism used to compare versions to determine which NamingSystem
       is more current."/> 
      <comment value="If set as a string, this is a FHIRPath expression that has two additional context
       variables passed in - %version1 and %version2 and will return a negative number
       if version1 is newer, a positive number if version2 and a 0 if the version ordering
       can't be successfully be determined."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.versionAlgorithm[x]"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <type> 
        <code value="Coding"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <binding> 
        <strength value="extensible"/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/version-algorithm"/> 
      </binding> 
    </element> 
    <element id="NamingSystem.name">
      <path value="NamingSystem.name"/> 
      <short value="Name for this naming system (computer friendly)"/> 
      <definition value="A natural language name identifying the naming system. This name should be usable
       as an identifier for the module by machine processing applications such as code
       generation."/> 
      <comment value="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.The&quot;symbolic name&quot;
       for an OID would be captured as an extension."/> 
      <requirements value="Support human navigation and code generation."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.name"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <condition value="cnl-0"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.title">
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="NamingSystem.title"/> 
      <short value="Title for this naming system (human friendly)"/> 
      <definition value="A short, descriptive, user-friendly title for the naming system."/> 
      <comment value="This title does not need to be machine-processing friendly and may contain punctuation,
       white-space, etc."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.title"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.status">
      <path value="NamingSystem.status"/> 
      <short value="draft | active | retired | unknown"/> 
      <definition value="The status of this naming system. Enables tracking the life-cycle of the content."/> 
      <comment value="Allows filtering of naming systems that are appropriate for use versus not.

See guidance around (not) making local changes to elements [here](canonicalresource.html#loca
      lization)."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.status"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="true"/> 
      <isModifierReason value="This is labeled as &quot;Is Modifier&quot; because applications should not use
       a retired {{title}} without due consideration"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="PublicationStatus"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/> 
        </extension> 
        <strength value="required"/> 
        <description value="The lifecycle status of an artifact."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/publication-status|5.0.0"/> 
      </binding> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.status"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.kind">
      <path value="NamingSystem.kind"/> 
      <short value="codesystem | identifier | root"/> 
      <definition value="Indicates the purpose for the naming system - what kinds of things does it make
       unique?"/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.kind"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <condition value="nsd-1"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="NamingSystemType"/> 
        </extension> 
        <strength value="required"/> 
        <description value="Identifies the purpose of the naming system."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/namingsystem-type|5.0.0"/> 
      </binding> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.class"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.experimental">
      <path value="NamingSystem.experimental"/> 
      <short value="For testing purposes, not real usage"/> 
      <definition value="A Boolean value to indicate that this naming system is authored for testing purposes
       (or education/evaluation/marketing) and is not intended to be used for genuine
       usage."/> 
      <comment value="Allows filtering of naming systems that are appropriate for use versus not."/> 
      <requirements value="Enables experimental content to be developed following the same lifecycle that
       would be used for a production-level naming system."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.experimental"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="boolean"/> 
      </type> 
      <meaningWhenMissing value="If absent, this resource is treated as though it is not experimental."/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.class"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.date">
      <path value="NamingSystem.date"/> 
      <short value="Date last changed"/> 
      <definition value="The date  (and optionally time) when the naming system was last significantly changed.
       The date must change 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 naming system changes."/> 
      <comment value="The date is often not tracked until the resource is published, but may be present
       on draft content. Note that this is not the same as the resource last-modified-date,
       since the resource may be a secondary representation of the naming system. Additional
       specific dates may be added as extensions or be found by consulting Provenances
       associated with past versions of the resource.

See guidance around (not) making local changes to elements [here](canonicalresource.html#loca
      lization)."/> 
      <alias value="Revision Date"/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.date"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="dateTime"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.recorded"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.publisher">
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="NamingSystem.publisher"/> 
      <short value="Name of the publisher/steward (organization or individual)"/> 
      <definition value="The name of the organization or individual responsible for the release and ongoing
       maintenance of the naming system."/> 
      <comment value="Usually an organization but may be an individual. The publisher (or steward) of
       the naming system is the organization or individual primarily responsible for the
       maintenance and upkeep of the naming 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 naming system.
       This item SHOULD be populated unless the information is available from context."/> 
      <requirements value="Helps establish the &quot;authority/credibility&quot; of the naming system.  May
       also allow for contact."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.publisher"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.witness"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.contact">
      <path value="NamingSystem.contact"/> 
      <short value="Contact details for the publisher"/> 
      <definition value="Contact details to assist a user in finding and communicating with the publisher."/> 
      <comment value="May be a web site, an email address, a telephone number, etc.

See guidance around (not) making local changes to elements [here](canonicalresource.html#loca
      lization)."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.contact"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.responsible">
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="NamingSystem.responsible"/> 
      <short value="Who maintains system namespace?"/> 
      <definition value="The name of the organization that is responsible for issuing identifiers or codes
       for this namespace and ensuring their non-collision."/> 
      <comment value="This is the primary organization.  Responsibility for some aspects of a namespace
       may be delegated."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.responsible"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.witness"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.type">
      <path value="NamingSystem.type"/> 
      <short value="e.g. driver,  provider,  patient, bank etc"/> 
      <definition value="Categorizes a naming system for easier search by grouping related naming systems."/> 
      <comment value="This will most commonly be used for identifier namespaces, but categories could
       potentially be useful for code systems and authorities as well."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.type"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="CodeableConcept"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="NamingSystemIdentifierSystemType"/> 
        </extension> 
        <strength value="preferred"/> 
        <description value="A coded type for an identifier that can be used to determine which identifier to
         use for a specific purpose."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/namingsystem-identifier-system-type"/> 
      </binding> 
    </element> 
    <element id="NamingSystem.description">
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="NamingSystem.description"/> 
      <short value="Natural language description of the naming system"/> 
      <definition value="A free text natural language description of the naming system from a consumer's
       perspective. Details about what the namespace identifies including scope, granularity,
       version labeling, etc."/> 
      <comment value="This description can be used to capture details such as comments about misuse,
       instructions for clinical use and interpretation, literature references, examples
       from the paper world, etc. It is not a rendering of the naming 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 naming system
       is presumed to be the predominant language in the place the naming system was created)."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.description"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="markdown"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.useContext">
      <path value="NamingSystem.useContext"/> 
      <short value="The context that the content is intended to support"/> 
      <definition value="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 naming system instances."/> 
      <comment value="When multiple useContexts are specified, there is no expectation that all or any
       of the contexts apply."/> 
      <requirements value="Assist in searching for appropriate content."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.useContext"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="UsageContext"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.jurisdiction">
      <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
        <valueCode value="deprecated"/> 
      </extension> 
      <path value="NamingSystem.jurisdiction"/> 
      <short value="Intended jurisdiction for naming system (if applicable)"/> 
      <definition value="A legal or geographic region in which the naming system is intended to be used."/> 
      <comment value="It may be possible for the naming system to be used in jurisdictions other than
       those for which it was originally designed or intended.

DEPRECATION NOTE: For consistency, implementations are encouraged to migrate to
       using the new 'jurisdiction' code in the useContext element.  (I.e. useContext.code
       indicating http://terminology.hl7.org/CodeSystem/usage-context-type#jurisdiction
       and useContext.valueCodeableConcept indicating the jurisdiction.)"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.jurisdiction"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="CodeableConcept"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Jurisdiction"/> 
        </extension> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/> 
        </extension> 
        <strength value="extensible"/> 
        <description value="Countries and regions within which this artifact is targeted for use."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/jurisdiction"/> 
      </binding> 
    </element> 
    <element id="NamingSystem.purpose">
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="NamingSystem.purpose"/> 
      <short value="Why this naming system is defined"/> 
      <definition value="Explanation of why this naming system is needed and why it has been designed as
       it has."/> 
      <comment value="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."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.purpose"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="markdown"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.why[x]"/> 
      </mapping> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.copyright">
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="NamingSystem.copyright"/> 
      <short value="Use and/or publishing restrictions"/> 
      <definition value="A copyright statement relating to the naming system and/or its contents. Copyright
       statements are generally legal restrictions on the use and publishing of the naming
       system."/> 
      <requirements value="Consumers must be able to determine any legal restrictions on the use of the naming
       system and/or its content."/> 
      <alias value="License"/> 
      <alias value="Restrictions"/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.copyright"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="markdown"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.copyrightLabel">
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="NamingSystem.copyrightLabel"/> 
      <short value="Copyright holder and year(s)"/> 
      <definition value="A short string (&lt;50 characters), suitable for inclusion in a page footer that
       identifies the copyright holder, effective period, and optionally whether rights
       are resctricted. (e.g. 'All rights reserved', 'Some rights reserved')."/> 
      <comment value="The (c) symbol should NOT be included in this string. It will be added by software
       when rendering the notation. Full details about licensing, restrictions, warrantees,
       etc. goes in the more general 'copyright' element."/> 
      <requirements value="Defines the content expected to be rendered in all representations of the artifact."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.copyrightLabel"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.approvalDate">
      <path value="NamingSystem.approvalDate"/> 
      <short value="When the NamingSystem was approved by publisher"/> 
      <definition value="The date on which the resource content was approved by the publisher. Approval
       happens once when the content is officially approved for usage."/> 
      <comment value="The 'date' element may be more recent than the approval date because of minor changes
       or editorial corrections.

See guidance around (not) making local changes to elements [here](canonicalresource.html#loca
      lization)."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.approvalDate"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="date"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.lastReviewDate">
      <path value="NamingSystem.lastReviewDate"/> 
      <short value="When the NamingSystem was last reviewed by the publisher"/> 
      <definition value="The date on which the resource content was last reviewed. Review happens periodically
       after approval but does not change the original approval date."/> 
      <comment value="If specified, this date follows the original approval date.

See guidance around (not) making local changes to elements [here](canonicalresource.html#loca
      lization)."/> 
      <requirements value="Gives a sense of how &quot;current&quot; the content is.  Resources that have not
       been reviewed in a long time may have a risk of being less appropriate/relevant."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.lastReviewDate"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="date"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.effectivePeriod">
      <path value="NamingSystem.effectivePeriod"/> 
      <short value="When the NamingSystem is expected to be used"/> 
      <definition value="The period during which the NamingSystem content was or is planned to be in active
       use."/> 
      <comment value="The effective period for a NamingSystem determines when the content is applicable
       for usage and is independent of publication and review dates. For example, a NamingSystem
       intended to be used for the year 2016 might be published in 2015.

See guidance around (not) making local changes to elements [here](canonicalresource.html#loca
      lization)."/> 
      <requirements value="Allows establishing a transition before a resource comes into effect and also allows
       for a sunsetting process when new versions of the NamingSystem are or are expected
       to be used instead."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.effectivePeriod"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Period"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.topic">
      <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
        <valueCode value="deprecated"/> 
      </extension> 
      <path value="NamingSystem.topic"/> 
      <short value="E.g. Education, Treatment, Assessment, etc"/> 
      <definition value="Descriptions related to the content of the NamingSystem. Topics provide a high-level
       categorization as well as keywords for the NamingSystem that can be useful for
       filtering and searching."/> 
      <comment value="DEPRECATION NOTE: For consistency, implementations are encouraged to migrate to
       using the new 'topic' code in the useContext element.  (I.e. useContext.code indicating
       http://terminology.hl7.org/CodeSystem/usage-context-type#topic and useContext.valueCodeableCo
      ncept indicating the topic)"/> 
      <requirements value="Repositories must be able to determine how to categorize the NamingSystem so that
       it can be found by topical and keyword searches."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.topic"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="CodeableConcept"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="DefinitionTopic"/> 
        </extension> 
        <strength value="example"/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/definition-topic"/> 
      </binding> 
    </element> 
    <element id="NamingSystem.author">
      <path value="NamingSystem.author"/> 
      <short value="Who authored the CodeSystem"/> 
      <definition value="An individiual or organization primarily involved in the creation and maintenance
       of the NamingSystem."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.author"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.editor">
      <path value="NamingSystem.editor"/> 
      <short value="Who edited the NamingSystem"/> 
      <definition value="An individual or organization primarily responsible for internal coherence of the
       NamingSystem."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.editor"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.reviewer">
      <path value="NamingSystem.reviewer"/> 
      <short value="Who reviewed the NamingSystem"/> 
      <definition value="An individual or organization asserted by the publisher to be primarily responsible
       for review of some aspect of the NamingSystem."/> 
      <comment value="See guidance around (not) making local changes to elements [here](canonicalresource.html#loca
      lization)."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.reviewer"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.endorser">
      <path value="NamingSystem.endorser"/> 
      <short value="Who endorsed the NamingSystem"/> 
      <definition value="An individual or organization asserted by the publisher to be responsible for officially
       endorsing the NamingSystem for use in some setting."/> 
      <comment value="See guidance around (not) making local changes to elements [here](canonicalresource.html#loca
      lization)."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.endorser"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.relatedArtifact">
      <path value="NamingSystem.relatedArtifact"/> 
      <short value="Additional documentation, citations, etc"/> 
      <definition value="Related artifacts such as additional documentation, justification, dependencies,
       bibliographic references, and predecessor and successor artifacts."/> 
      <comment value="Each related artifact is either an attachment, or a reference to another resource,
       but not both."/> 
      <requirements value="A NamingSystem must be able to provide enough information for consumers of the
       content (and/or interventions or results produced by the content) to be able to
       determine and understand the justification for and evidence in support of the content."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.relatedArtifact"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="RelatedArtifact"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.usage">
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable">
        <valueBoolean value="true"/> 
      </extension> 
      <path value="NamingSystem.usage"/> 
      <short value="How/where is it used"/> 
      <definition value="Provides guidance on the use of the namespace, including the handling of formatting
       characters, use of upper vs. lower case, etc."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.usage"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.uniqueId">
      <path value="NamingSystem.uniqueId"/> 
      <short value="Unique identifiers used for system"/> 
      <definition value="Indicates how the system may be identified when referenced in electronic exchange."/> 
      <comment value="Multiple identifiers may exist, either due to duplicate registration, regional
       rules, needs of different communication technologies, etc."/> 
      <min value="1"/> 
      <max value="*"/> 
      <base> 
        <path value="NamingSystem.uniqueId"/> 
        <min value="1"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="BackboneElement"/> 
      </type> 
      <condition value="nsd-1"/> 
      <condition value="nsd-2"/> 
      <condition value="nsd-3"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.uniqueId.id">
      <path value="NamingSystem.uniqueId.id"/> 
      <representation value="xmlAttr"/> 
      <short value="Unique id for inter-element referencing"/> 
      <definition value="Unique id for the element within a resource (for internal references). This may
       be any string value that does not contain spaces."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="Element.id"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUrl value="string"/> 
        </extension> 
        <code value="http://hl7.org/fhirpath/System.String"/> 
      </type> 
      <condition value="ele-1"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.uniqueId.extension">
      <path value="NamingSystem.uniqueId.extension"/> 
      <short value="Additional content defined by implementations"/> 
      <definition value="May be used to represent additional information that is not part of the basic definition
       of the element. To make the use of extensions safe and managable, there is a strict
       set of governance applied to the definition and use of extensions. Though any implementer
       can define an extension, there is a set of requirements that SHALL be met as part
       of the definition of the extension."/> 
      <comment value="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."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="Element.extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="n/a"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.uniqueId.modifierExtension">
      <path value="NamingSystem.uniqueId.modifierExtension"/> 
      <short value="Extensions that cannot be ignored even if unrecognized"/> 
      <definition value="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 in which it is
       contained and/or the understanding of the containing element's descendants. Usually
       modifier elements provide negation or qualification. To make the use of extensions
       safe and managable, there is a strict set of governance applied to the definition
       and use of extensions. Though any implementer can define an extension, there is
       a set of requirements that SHALL be met as part of the definition of the extension.
       Applications processing a resource are required to check for modifier extensions.

Modifier extensions SHALL NOT change the meaning of any elements on Resource or
       DomainResource (including cannot change the meaning of modifierExtension itself)."/> 
      <comment value="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."/> 
      <requirements value="Modifier extensions allow for extensions that *cannot* be safely ignored to be
       clearly distinguished from the vast majority of extensions which can be safely
       ignored.  This promotes interoperability by eliminating the need for implementers
       to prohibit the presence of extensions. For further information, see the [definition
       of modifier extensions](extensibility.html#modifierExtension)."/> 
      <alias value="extensions"/> 
      <alias value="user content"/> 
      <alias value="modifiers"/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="BackboneElement.modifierExtension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <constraint> 
        <key value="ext-1"/> 
        <severity value="error"/> 
        <human value="Must have either extensions or value[x], not both"/> 
        <expression value="extension.exists() != value.exists()"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
      </constraint> 
      <isModifier value="true"/> 
      <isModifierReason value="Modifier extensions are expected to modify the meaning or interpretation of the
       element that contains them"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.uniqueId.type">
      <path value="NamingSystem.uniqueId.type"/> 
      <short value="oid | uuid | uri | iri-stem | v2csmnemonic | other"/> 
      <definition value="Identifies the unique identifier scheme used for this particular identifier."/> 
      <comment value="Different identifier types may be used in different types of communications (OIDs
       for v3, URIs for FHIR, etc.).  Other includes RUIDs from v3, standard v2 code name
       strings, etc. Preferred identifiers for the same identifier type SHOULD NOT overlap
       by period."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.uniqueId.type"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="code"/> 
      </type> 
      <condition value="nsd-1"/> 
      <condition value="nsd-2"/> 
      <condition value="nsd-3"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <binding> 
        <extension url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="NamingSystemIdentifierType"/> 
        </extension> 
        <strength value="required"/> 
        <description value="Identifies the style of unique identifier used to identify a namespace."/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/namingsystem-identifier-type|5.0.0"/> 
      </binding> 
    </element> 
    <element id="NamingSystem.uniqueId.value">
      <path value="NamingSystem.uniqueId.value"/> 
      <short value="The unique identifier"/> 
      <definition value="The string that should be sent over the wire to identify the code system or identifier
       system."/> 
      <comment value="If the value is a URI intended for use as FHIR system identifier, the URI should
       not contain &quot;\&quot; or &quot;?&quot; or &quot;,&quot; since this makes escaping
       very difficult."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.uniqueId.value"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="w5"/> 
        <map value="FiveWs.identifier"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.uniqueId.preferred">
      <path value="NamingSystem.uniqueId.preferred"/> 
      <short value="Is this the id that should be used for this type"/> 
      <definition value="Indicates whether this identifier is the &quot;preferred&quot; identifier of this
       type."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.uniqueId.preferred"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="boolean"/> 
      </type> 
      <meaningWhenMissing value="If there are multiple ids, and one is labeled &quot;preferred&quot;, then the assumption
       is that the others are not preferred. In the absence of any id marked as preferred,
       no inference can be drawn"/> 
      <condition value="nsd-2"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.uniqueId.comment">
      <path value="NamingSystem.uniqueId.comment"/> 
      <short value="Notes about identifier usage"/> 
      <definition value="Notes about the past or intended usage of this identifier."/> 
      <comment value="e.g. &quot;must be used in Germany&quot; or &quot;was initially published in error
       with this value&quot;."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.uniqueId.comment"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="string"/> 
      </type> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.uniqueId.period">
      <path value="NamingSystem.uniqueId.period"/> 
      <short value="When is identifier valid?"/> 
      <definition value="Identifies the period of time over which this identifier is considered appropriate
       to refer to the naming system.  Outside of this window, the identifier might be
       non-deterministic."/> 
      <comment value="Within a registry, a given identifier should only be &quot;active&quot; for a single
       namespace at a time.  (Ideally, an identifier should only ever be associated with
       a single namespace across all time).

The nuance of identifier deprecation is not represented with a separate element.
       When a determination is made that an identifier should not be used, the validity
       period end date is updated with the date the identifier is deemed to be deprecated.
       The identifier should no longer be used once the period end date is reached."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.uniqueId.period"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="Period"/> 
      </type> 
      <condition value="nsd-3"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.uniqueId.authoritative">
      <path value="NamingSystem.uniqueId.authoritative"/> 
      <short value="Whether the identifier is authoritative"/> 
      <definition value="Indicates whether this identifier ie endorsed by the official owner of the associated
       naming system."/> 
      <min value="0"/> 
      <max value="1"/> 
      <base> 
        <path value="NamingSystem.uniqueId.authoritative"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="boolean"/> 
      </type> 
      <condition value="nsd-3"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children"/> 
        <expression value="hasValue() or (children().count() &gt; id.count())"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
  </snapshot> 
  <differential> 
    <element id="NamingSystem">
      <path value="NamingSystem"/> 
      <min value="1"/> 
      <max value="1"/> 
    </element> 
    <element id="NamingSystem.extension:knowledgeRepresentationLevel">
      <path value="NamingSystem.extension"/> 
      <sliceName value="knowledgeRepresentationLevel"/> 
      <min value="0"/> 
      <max value="*"/> 
      <type> 
        <code value="Extension"/> 
        <profile value="http://hl7.org/fhir/StructureDefinition/cqf-knowledgeRepresentationLevel"/> 
      </type> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.url">
      <path value="NamingSystem.url"/> 
      <min value="1"/> 
      <max value="1"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.version">
      <path value="NamingSystem.version"/> 
      <min value="1"/> 
      <max value="1"/> 
      <type> 
        <code value="string"/> 
      </type> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.versionAlgorithm[x]">
      <path value="NamingSystem.versionAlgorithm[x]"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.name">
      <path value="NamingSystem.name"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.title">
      <path value="NamingSystem.title"/> 
      <min value="1"/> 
      <max value="1"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.status">
      <path value="NamingSystem.status"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.experimental">
      <path value="NamingSystem.experimental"/> 
      <min value="0"/> 
      <max value="1"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.publisher">
      <path value="NamingSystem.publisher"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.description">
      <path value="NamingSystem.description"/> 
      <min value="1"/> 
      <max value="1"/> 
      <mustSupport value="true"/> 
    </element> 
  </differential> 
</StructureDefinition>