Release 4B Ballot #1

This page is part of the FHIR Specification (v4.1.0: Release 4B Ballot #1). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R4B R4 R3

Extension-capabilitystatement-search-parameter-combination.xml

FHIR Infrastructure Work GroupMaturity Level: N/AStandards Status: Informative

Raw XML (canonical form + also see XML Format Specification)

search-parameter-combination

<?xml version="1.0" encoding="UTF-8"?>

<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="capabilitystatement-search-parameter-combination"/> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
    <valueCode value="fhir"/> 
  </extension> 
  <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
    <valueInteger value="1"/> 
  </extension> 
  <url value="http://hl7.org/fhir/StructureDefinition/capabilitystatement-search-parameter-combination"/> 
  <version value="4.1.0"/> 
  <name value="search-parameter-combination"/> 
  <title value="Search Parameter Combination"/> 
  <status value="draft"/> 
  <date value="2014-04-12"/> 
  <publisher value="Health Level Seven, Inc. - [WG Name] WG"/> 
  <contact> 
    <telecom> 
      <system value="url"/> 
      <value value="http://hl7.org/special/committees/fhir.htm"/> 
    </telecom> 
  </contact> 
  <description value="This extension defines a possible search parameter combination,  by listing a set of search
   parameters and indicating whether they are required or optional. If a search combination
   is specified, clients should expect that they must submit a search that meets one of the
   required combinations or the search will be unsuccessful. If multiple search parameter
   combinations are specified, a client may pick between them, and supply the minimal required
   parameters for any of the combinations."/> 
  <fhirVersion value="4.1.0"/> 
  <mapping> 
    <identity value="v2"/> 
    <uri value="http://hl7.org/v2"/> 
    <name value="HL7 v2 Mapping"/> 
  </mapping> 
  <mapping> 
    <identity value="rim"/> 
    <uri value="http://hl7.org/v3"/> 
    <name value="RIM Mapping"/> 
  </mapping> 
  <kind value="complex-type"/> 
  <abstract value="false"/> 
  <context> 
    <type value="element"/> 
    <expression value="CapabilityStatement.rest.resource"/> 
  </context> 
  <type value="Extension"/> 
  <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension"/> 
  <derivation value="constraint"/> 
  <snapshot> 
    <element id="Extension">
      <path value="Extension"/> 
      <short value="An allowable parameter combination"/> 
      <definition value="This extension defines a possible search parameter combination,  by listing a set of search
       parameters and indicating whether they are required or optional. If a search combination
       is specified, clients should expect that they must submit a search that meets one of the
       required combinations or the search will be unsuccessful. If multiple search parameter
       combinations are specified, a client may pick between them, and supply the minimal required
       parameters for any of the combinations."/> 
      <comment value="For example, on the Patient Resource  you could use this to state support for searching
       by Patient.name and Patient.gender is required."/> 
      <min value="0"/> 
      <max value="*"/> 
      <base> 
        <path value="Extension"/> 
        <min value="0"/> 
        <max value="*"/> 
      </base> 
      <condition value="ele-1"/> 
      <constraint> 
        <key value="ele-1"/> 
        <severity value="error"/> 
        <human value="All FHIR elements must have a @value or children unless an empty Parameters resource"/> 
        <expression value="hasValue() or (children().count() &gt; id.count()) or $this is Parameters"/> 
        <xpath value="@value|f:*|h:div|self::f:Parameters"/> 
        <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> 
      <isModifier value="false"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.id">
      <path value="Extension.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">
          <valueUri 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="Extension.extension">
      <path value="Extension.extension"/> 
      <slicing> 
        <discriminator> 
          <type value="value"/> 
          <path value="url"/> 
        </discriminator> 
        <description value="Extensions are always sliced by (at least) url"/> 
        <rules value="open"/> 
      </slicing> 
      <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="Extension.extension:required">
      <path value="Extension.extension"/> 
      <sliceName value="required"/> 
      <short value="A required search parameter name"/> 
      <definition value="A search parameter name in the combination which is required."/> 
      <min value="1"/> 
      <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="v2"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.extension:required.id">
      <path value="Extension.extension.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">
          <valueUri 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="Extension.extension:required.extension">
      <path value="Extension.extension.extension"/> 
      <slicing> 
        <discriminator> 
          <type value="value"/> 
          <path value="url"/> 
        </discriminator> 
        <description value="Extensions are always sliced by (at least) url"/> 
        <rules value="open"/> 
      </slicing> 
      <short value="Extension"/> 
      <definition value="An Extension"/> 
      <min value="0"/> 
      <max value="0"/> 
      <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"/> 
    </element> 
    <element id="Extension.extension:required.url">
      <path value="Extension.extension.url"/> 
      <representation value="xmlAttr"/> 
      <short value="identifies the meaning of the extension"/> 
      <definition value="Source of the definition for the extension code - a logical name or a URL."/> 
      <comment value="The definition may point directly to a computable or human-readable definition of the
       extensibility codes, or it may be a logical URI as declared in some other specification.
       The definition SHALL be a URI for the Structure Definition defining the extension."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="Extension.url"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="uri"/> 
      </type> 
      <fixedUri value="required"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.extension:required.value[x]">
      <path value="Extension.extension.value[x]"/> 
      <short value="Value of extension"/> 
      <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](extensi
      bility.html) for a list)."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="Extension.value[x]"/> 
        <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> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.extension:optional">
      <path value="Extension.extension"/> 
      <sliceName value="optional"/> 
      <short value="An optional search parameter name"/> 
      <definition value="A search parameter name in the combination which is optional."/> 
      <comment value="If a defined parameter is not listed as a required or optional parameter, the implication
       is that the parameter is not supported with this combination. Servers may ignore It, though
       some may return an error if it is used."/> 
      <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="v2"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.extension:optional.id">
      <path value="Extension.extension.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">
          <valueUri 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="Extension.extension:optional.extension">
      <path value="Extension.extension.extension"/> 
      <slicing> 
        <discriminator> 
          <type value="value"/> 
          <path value="url"/> 
        </discriminator> 
        <description value="Extensions are always sliced by (at least) url"/> 
        <rules value="open"/> 
      </slicing> 
      <short value="Extension"/> 
      <definition value="An Extension"/> 
      <min value="0"/> 
      <max value="0"/> 
      <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"/> 
    </element> 
    <element id="Extension.extension:optional.url">
      <path value="Extension.extension.url"/> 
      <representation value="xmlAttr"/> 
      <short value="identifies the meaning of the extension"/> 
      <definition value="Source of the definition for the extension code - a logical name or a URL."/> 
      <comment value="The definition may point directly to a computable or human-readable definition of the
       extensibility codes, or it may be a logical URI as declared in some other specification.
       The definition SHALL be a URI for the Structure Definition defining the extension."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="Extension.url"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="uri"/> 
      </type> 
      <fixedUri value="optional"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.extension:optional.value[x]">
      <path value="Extension.extension.value[x]"/> 
      <short value="Value of extension"/> 
      <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](extensi
      bility.html) for a list)."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="Extension.value[x]"/> 
        <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> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.url">
      <path value="Extension.url"/> 
      <representation value="xmlAttr"/> 
      <short value="identifies the meaning of the extension"/> 
      <definition value="Source of the definition for the extension code - a logical name or a URL."/> 
      <comment value="The definition may point directly to a computable or human-readable definition of the
       extensibility codes, or it may be a logical URI as declared in some other specification.
       The definition SHALL be a URI for the Structure Definition defining the extension."/> 
      <min value="1"/> 
      <max value="1"/> 
      <base> 
        <path value="Extension.url"/> 
        <min value="1"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
          <valueUri value="uri"/> 
        </extension> 
        <code value="http://hl7.org/fhirpath/System.String"/> 
      </type> 
      <fixedUri value="http://hl7.org/fhir/StructureDefinition/capabilitystatement-search-parameter-combination"/> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.value[x]">
      <path value="Extension.value[x]"/> 
      <short value="Value of extension"/> 
      <definition value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](extensi
      bility.html) for a list)."/> 
      <min value="0"/> 
      <max value="0"/> 
      <base> 
        <path value="Extension.value[x]"/> 
        <min value="0"/> 
        <max value="1"/> 
      </base> 
      <type> 
        <code value="base64Binary"/> 
      </type> 
      <type> 
        <code value="boolean"/> 
      </type> 
      <type> 
        <code value="canonical"/> 
      </type> 
      <type> 
        <code value="code"/> 
      </type> 
      <type> 
        <code value="date"/> 
      </type> 
      <type> 
        <code value="dateTime"/> 
      </type> 
      <type> 
        <code value="decimal"/> 
      </type> 
      <type> 
        <code value="id"/> 
      </type> 
      <type> 
        <code value="instant"/> 
      </type> 
      <type> 
        <code value="integer"/> 
      </type> 
      <type> 
        <code value="markdown"/> 
      </type> 
      <type> 
        <code value="oid"/> 
      </type> 
      <type> 
        <code value="positiveInt"/> 
      </type> 
      <type> 
        <code value="string"/> 
      </type> 
      <type> 
        <code value="time"/> 
      </type> 
      <type> 
        <code value="unsignedInt"/> 
      </type> 
      <type> 
        <code value="uri"/> 
      </type> 
      <type> 
        <code value="url"/> 
      </type> 
      <type> 
        <code value="uuid"/> 
      </type> 
      <type> 
        <code value="Address"/> 
      </type> 
      <type> 
        <code value="Age"/> 
      </type> 
      <type> 
        <code value="Annotation"/> 
      </type> 
      <type> 
        <code value="Attachment"/> 
      </type> 
      <type> 
        <code value="CodeableConcept"/> 
      </type> 
      <type> 
        <code value="Coding"/> 
      </type> 
      <type> 
        <code value="ContactPoint"/> 
      </type> 
      <type> 
        <code value="Count"/> 
      </type> 
      <type> 
        <code value="Distance"/> 
      </type> 
      <type> 
        <code value="Duration"/> 
      </type> 
      <type> 
        <code value="HumanName"/> 
      </type> 
      <type> 
        <code value="Identifier"/> 
      </type> 
      <type> 
        <code value="Money"/> 
      </type> 
      <type> 
        <code value="Period"/> 
      </type> 
      <type> 
        <code value="Quantity"/> 
      </type> 
      <type> 
        <code value="Range"/> 
      </type> 
      <type> 
        <code value="Ratio"/> 
      </type> 
      <type> 
        <code value="Reference"/> 
      </type> 
      <type> 
        <code value="SampledData"/> 
      </type> 
      <type> 
        <code value="Signature"/> 
      </type> 
      <type> 
        <code value="Timing"/> 
      </type> 
      <type> 
        <code value="ContactDetail"/> 
      </type> 
      <type> 
        <code value="Contributor"/> 
      </type> 
      <type> 
        <code value="DataRequirement"/> 
      </type> 
      <type> 
        <code value="Expression"/> 
      </type> 
      <type> 
        <code value="ParameterDefinition"/> 
      </type> 
      <type> 
        <code value="RelatedArtifact"/> 
      </type> 
      <type> 
        <code value="TriggerDefinition"/> 
      </type> 
      <type> 
        <code value="UsageContext"/> 
      </type> 
      <type> 
        <code value="Dosage"/> 
      </type> 
      <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> 
      <isModifier value="false"/> 
      <isSummary value="false"/> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
  </snapshot> 
  <differential> 
    <element id="Extension">
      <path value="Extension"/> 
      <short value="An allowable parameter combination"/> 
      <definition value="This extension defines a possible search parameter combination,  by listing a set of search
       parameters and indicating whether they are required or optional. If a search combination
       is specified, clients should expect that they must submit a search that meets one of the
       required combinations or the search will be unsuccessful. If multiple search parameter
       combinations are specified, a client may pick between them, and supply the minimal required
       parameters for any of the combinations."/> 
      <comment value="For example, on the Patient Resource  you could use this to state support for searching
       by Patient.name and Patient.gender is required."/> 
      <min value="0"/> 
      <max value="*"/> 
      <isModifier value="false"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.extension:required">
      <path value="Extension.extension"/> 
      <sliceName value="required"/> 
      <short value="A required search parameter name"/> 
      <definition value="A search parameter name in the combination which is required."/> 
      <min value="1"/> 
      <max value="*"/> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <isModifier value="false"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.extension:required.extension">
      <path value="Extension.extension.extension"/> 
      <max value="0"/> 
    </element> 
    <element id="Extension.extension:required.url">
      <path value="Extension.extension.url"/> 
      <type> 
        <code value="uri"/> 
      </type> 
      <fixedUri value="required"/> 
    </element> 
    <element id="Extension.extension:required.value[x]">
      <path value="Extension.extension.value[x]"/> 
      <min value="1"/> 
      <type> 
        <code value="string"/> 
      </type> 
    </element> 
    <element id="Extension.extension:optional">
      <path value="Extension.extension"/> 
      <sliceName value="optional"/> 
      <short value="An optional search parameter name"/> 
      <definition value="A search parameter name in the combination which is optional."/> 
      <comment value="If a defined parameter is not listed as a required or optional parameter, the implication
       is that the parameter is not supported with this combination. Servers may ignore It, though
       some may return an error if it is used."/> 
      <min value="0"/> 
      <max value="*"/> 
      <type> 
        <code value="Extension"/> 
      </type> 
      <isModifier value="false"/> 
      <mapping> 
        <identity value="v2"/> 
        <map value="N/A"/> 
      </mapping> 
      <mapping> 
        <identity value="rim"/> 
        <map value="N/A"/> 
      </mapping> 
    </element> 
    <element id="Extension.extension:optional.extension">
      <path value="Extension.extension.extension"/> 
      <max value="0"/> 
    </element> 
    <element id="Extension.extension:optional.url">
      <path value="Extension.extension.url"/> 
      <type> 
        <code value="uri"/> 
      </type> 
      <fixedUri value="optional"/> 
    </element> 
    <element id="Extension.extension:optional.value[x]">
      <path value="Extension.extension.value[x]"/> 
      <min value="1"/> 
      <type> 
        <code value="string"/> 
      </type> 
    </element> 
    <element id="Extension.url">
      <path value="Extension.url"/> 
      <fixedUri value="http://hl7.org/fhir/StructureDefinition/capabilitystatement-search-parameter-combination"/> 
    </element> 
    <element id="Extension.value[x]">
      <path value="Extension.value[x]"/> 
      <min value="0"/> 
      <max value="0"/> 
    </element> 
  </differential> 
</StructureDefinition> 

Usage note: every effort has been made to ensure that the examples are correct and useful, but they are not a normative part of the specification.