This page is part of the FHIR Specification (v5.0.0-ballot: FHIR R5 Ballot Preview). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions
StructureDefinition: PublishableNamingSystem - XML

Vocabulary Work Group
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PublishableNamingSystem
<?xml version="1.0" encoding="UTF-8"?>

<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="publishablenamingsystem"/> 
  <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/publishablenamingsystem"/> 
  <identifier> 
    <system value="urn:ietf:rfc:3986"/> 
    <value value="urn:oid:2.16.840.1.113883.4.642.5.1261"/> 
  </identifier> 
  <version value="5.0.0-ballot"/> 
  <name value="PublishableNamingSystem"/> 
  <title value="Publishable NamingSystem"/> 
  <status value="draft"/> 
  <experimental value="false"/> 
  <date value="2020-12-28T16:55:11+11:00"/> 
  <publisher value="HL7"/> 
  <description value="Defines and enforces the minimum expectations for publication and distribution of a naming
   system, typically as part of an artifact repository or implementation guide publication"/> 
  <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/shareablenamingsystem"/> 
  <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}')"/> 
        <xpath value="not(exists(f:name/@value)) or matches(f:name/@value, '[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')"/> 
        <xpath value="not(f:kind/@value='root' and f:uniqueId/f:type/@value='uuid')"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/NamingSystem"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="w5"/> 
        <map value="conformance.terminology"/> 
      </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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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
       it's 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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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 it's 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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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-maxValueSet">
          <valueCanonical value="http://hl7.org/fhir/ValueSet/all-languages"/> 
        </extension> 
        <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="preferred"/> 
        <description value="IETF language tag"/> 
        <valueSet value="http://hl7.org/fhir/ValueSet/languages"/> 
      </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> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/> 
        <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])"/> 
        <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 manageable, there is
       a strict set of governance applied to the definition and use of extensions. Though any
       implementer is allowed to define an extension, there is a set of requirements that SHALL
       be met as part of the definition of the extension. Applications processing a resource
       are required to check for modifier extensions.

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.ht
      ml#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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/> 
        <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="url.matches('([^|#])*')"/> 
        <xpath value="not(exists(@value)) or matches(@value, '([^|#])*')"/> 
        <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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.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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.title">
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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."/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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-ballot"/> 
      </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> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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-ballot"/> 
      </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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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 published. 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="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."/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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.recorded"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.publisher">
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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."/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.responsible">
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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">
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
    </element> 
    <element id="NamingSystem.jurisdiction">
      <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."/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <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">
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <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">
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </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."/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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"/> 
      <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."/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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 measure intended
       to be used for the year 2016 might be published in 2015."/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <isModifier value="false"/> 
      <isSummary value="true"/> 
      <mapping> 
        <identity value="objimpl"/> 
        <map value="no-gen-base"/> 
      </mapping> 
    </element> 
    <element id="NamingSystem.topic">
      <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="This element provides topical categorization and keywords for the NamingSystem, as opposed
       to the more structured context-of-use information provided in the useContext element"/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="true"/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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 primarily responsible for review of some aspect of the NamingSystem."/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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 responsible for officially endorsing the NamingSystem for
       use in some setting."/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </constraint> 
      <mustSupport value="false"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
    </element> 
    <element id="NamingSystem.usage">
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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> 
      <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 manageable, there is a strict set
       of governance  applied to the definition and use of extensions. Though any implementer
       can define an extension, there is a set of requirements that SHALL be met as part of the
       definition of the extension."/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/> 
        <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 manageable,
       there is a strict set of governance applied to the definition and use of extensions. Though
       any implementer can define an extension, there is a set of requirements that SHALL be
       met as part of the definition of the extension. 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.ht
      ml#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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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()"/> 
        <xpath value="exists(f:extension)!=exists(f:*[starts-with(local-name(.), &quot;value&quot;)])"/> 
        <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 | 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> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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-ballot"/> 
      </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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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"/> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </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()"/> 
        <xpath value="not(exists(for $type in distinct-values(f:uniqueId/f:type/@value) return if (count(f:uniqueId[f:type
        /@value=$type and f:preferred/@value=true()])&gt;1) then $type else ()))"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/NamingSystem"/> 
      </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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <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> 
      <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())"/> 
        <xpath value="@value|f:*|h:div"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/Element"/> 
      </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).isDistinct().select(period).isDistinct()"/> 
        <xpath value="count(f:uniqueID)=count(distinct-values(f:uniqueID/f:period/@value)) or not(exists(for
         $type in distinct-values(f:uniqueId/f:type/@value) return if (count(f:uniqueId[f:type/@value=$type
         and f:authoritative/@value=true()])&gt;1) then $type else ()))"/> 
        <source value="http://hl7.org/fhir/StructureDefinition/NamingSystem"/> 
      </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.identifier">
      <path value="NamingSystem.identifier"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.date">
      <path value="NamingSystem.date"/> 
      <min value="1"/> 
      <max value="1"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.contact">
      <path value="NamingSystem.contact"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.useContext">
      <path value="NamingSystem.useContext"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.jurisdiction">
      <path value="NamingSystem.jurisdiction"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.purpose">
      <path value="NamingSystem.purpose"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.copyright">
      <path value="NamingSystem.copyright"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.approvalDate">
      <path value="NamingSystem.approvalDate"/> 
    </element> 
    <element id="NamingSystem.lastReviewDate">
      <path value="NamingSystem.lastReviewDate"/> 
    </element> 
    <element id="NamingSystem.effectivePeriod">
      <path value="NamingSystem.effectivePeriod"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.topic">
      <path value="NamingSystem.topic"/> 
      <mustSupport value="true"/> 
    </element> 
    <element id="NamingSystem.author">
      <path value="NamingSystem.author"/> 
    </element> 
    <element id="NamingSystem.editor">
      <path value="NamingSystem.editor"/> 
    </element> 
    <element id="NamingSystem.reviewer">
      <path value="NamingSystem.reviewer"/> 
    </element> 
    <element id="NamingSystem.endorser">
      <path value="NamingSystem.endorser"/> 
    </element> 
    <element id="NamingSystem.relatedArtifact">
      <path value="NamingSystem.relatedArtifact"/> 
    </element> 
  </differential> 
</StructureDefinition>