Order Catalog Implementation Guide
current - CI Build

Order Catalog Implementation Guide, published by HL7 International - Orders and Observations Work Group. This is not an authorized publication; it is the continuous build for version current). This version is based on the current content of https://github.com/HL7/fhir-order-catalog/ and changes regularly. See the Directory of published versions

Resource Profile: CatalogMessageDefinition - XML Profile

XML representation of the CatalogMessageDefinition resource profile.

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<StructureDefinition xmlns="http://hl7.org/fhir">
  <id value="CatalogMessageDefinition"/>
  <text>
    <status value="extensions"/>
    <div xmlns="http://www.w3.org/1999/xhtml"><table border="0" cellpadding="0" cellspacing="0" style="border: 0px #F0F0F0 solid; font-size: 11px; font-family: verdana; vertical-align: top;"><tr style="border: 1px #F0F0F0 solid; font-size: 11px; font-family: verdana; vertical-align: top"><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://build.fhir.org/formats.html#table" title="The logical name of the element">Name</a></th><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://build.fhir.org/formats.html#table" title="Information about the use of the element">Flags</a></th><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://build.fhir.org/formats.html#table" title="Minimum and Maximum # of times the the element can appear in the instance">Card.</a></th><th style="width: 100px" class="hierarchy"><a href="http://build.fhir.org/formats.html#table" title="Reference to the type of the element">Type</a></th><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://build.fhir.org/formats.html#table" title="Additional information about the element">Description &amp; Constraints</a><span style="float: right"><a href="http://build.fhir.org/formats.html#table" title="Legend for this format"><img src="http://build.fhir.org/help16.png" alt="doco" style="background-color: inherit"/></a></span></th></tr><tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: white"><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck1.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_resource.png" alt="." style="background-color: white; background-color: inherit" title="Resource" class="hierarchy"/> <a href="StructureDefinition-CatalogMessageDefinition-definitions.html#MessageDefinition">MessageDefinition</a><a name="MessageDefinition"> </a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">0</span><span style="opacity: 0.5">..</span><span style="opacity: 0.5">*</span></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://build.fhir.org/messagedefinition.html">MessageDefinition</a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">A resource that defines a type of message that can be exchanged between systems</span></td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: #F7F7F7"><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck10.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_datatype.gif" alt="." style="background-color: #F7F7F7; background-color: inherit" title="Data Type" class="hierarchy"/> <a href="StructureDefinition-CatalogMessageDefinition-definitions.html#MessageDefinition.event[x]" title="Event code for messages conveying order-catalog content">event[x]</a><a name="MessageDefinition.event_x_"> </a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="padding-left: 3px; padding-right: 3px; color: white; background-color: red" title="This element must be supported">S</span></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">1</span><span style="opacity: 0.5">..</span><span style="opacity: 0.5">1</span></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://build.fhir.org/datatypes.html#Coding">Coding</a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">Event code<br/><span style="font-weight:bold">Binding: </span><a href="ValueSet-catalog-message-events-vs.html">Message event codes for exchanging order catalog content</a> (<a href="http://build.fhir.org/terminologies.html#extensible" title="To be conformant, the concept in this element SHALL be from the specified value set if any of the codes within the value set can apply to the concept being communicated.  If the value set does not cover the concept (based on human review), alternate codings (or, data type allowing, text) may be included instead.">extensible</a>): message events for messages conveying order-catalog content<br/><br/></td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: white"><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck10.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_element.gif" alt="." style="background-color: white; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-CatalogMessageDefinition-definitions.html#MessageDefinition.category">category</a><a name="MessageDefinition.category"> </a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">0</span><span style="opacity: 0.5">..</span><span style="opacity: 0.5">1</span></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a style="opacity: 0.5" href="http://build.fhir.org/datatypes.html#code">code</a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">consequence | currency | notification</span><br/><span style="font-weight:bold">Fixed Value: </span><span style="color: darkgreen">consequence</span></td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: #F7F7F7"><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck00.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin_end.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_element.gif" alt="." style="background-color: #F7F7F7; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-CatalogMessageDefinition-definitions.html#MessageDefinition.responseRequired">responseRequired</a><a name="MessageDefinition.responseRequired"> </a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="padding-left: 3px; padding-right: 3px; color: white; background-color: red" title="This element must be supported">S</span></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">1..<span style="opacity: 0.5">1</span></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a style="opacity: 0.5" href="http://build.fhir.org/datatypes.html#code">code</a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">always | on-error | never | on-success</span></td></tr>
<tr><td colspan="5" class="hierarchy"><br/><a href="http://build.fhir.org/formats.html#table" title="Legend for this format"><img src="http://build.fhir.org/help16.png" alt="doco" style="background-color: inherit"/> Documentation for this format</a></td></tr></table></div>
  </text>
  <url
       value="http://hl7.org/fhir/uv/order-catalog/StructureDefinition/CatalogMessageDefinition"/>
  <version value="current"/>
  <name value="CatalogMessageDefinition"/>
  <title value="Message definition for messaging order-catalog content"/>
  <status value="draft"/>
  <date value="2020-04-02"/>
  <publisher value="HL7 International - Orders and Observations Work Group"/>
  <contact>
    <telecom>
      <system value="url"/>
      <value value="http://hl7.org/Special/committees/orders"/>
    </telecom>
  </contact>
  <description
               value="This profile constrains MessageDefinition in the context of messaging the content of catalogs, in conformance with the FHIR messaging framework"/>
  <jurisdiction>
    <coding>
      <system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/>
      <code value="001"/>
    </coding>
  </jurisdiction>
  <purpose
           value="This profile specifies the event codes that are available for messaging the content of catalogs between a system owning a catalog and a system interested in the catalog content, in whole or in part."/>
  <fhirVersion value="5.0.0-snapshot1"/>
  <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>
  <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>
  <kind value="resource"/>
  <abstract value="false"/>
  <type value="MessageDefinition"/>
  <baseDefinition
                  value="http://hl7.org/fhir/StructureDefinition/MessageDefinition"/>
  <derivation value="constraint"/>
  <snapshot>
    <element id="MessageDefinition">
      <path value="MessageDefinition"/>
      <short
             value="A resource that defines a type of message that can be exchanged between systems"/>
      <definition
                  value="Defines the characteristics of a message that can be shared between systems, including the type of event that initiates the message, the content to be transmitted and what response(s), if any, are permitted."/>
      <comment value="This would be a MIF-level artifact."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="MessageDefinition"/>
        <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.matches('[A-Z]([A-Za-z0-9_]){0,254}')"/>
        <xpath
               value="not(exists(f:name/@value)) or matches(f:name/@value, '[A-Z]([A-Za-z0-9_]){0,254}')"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/MessageDefinition"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition"/>
      </mapping>
      <mapping>
        <identity value="v2"/>
        <map value="N/A"/>
      </mapping>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="infrastructure.exchange"/>
      </mapping>
    </element>
    <element id="MessageDefinition.id">
      <path value="MessageDefinition.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="Typically, the resource has an id except for cases like the create operation, conditional updates."/>
      <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="MessageDefinition.meta">
      <path value="MessageDefinition.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="MessageDefinition.implicitRules">
      <path value="MessageDefinition.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="MessageDefinition.language">
      <path value="MessageDefinition.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="MessageDefinition.text">
      <path value="MessageDefinition.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="MessageDefinition.contained">
      <path value="MessageDefinition.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."/>
      <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="MessageDefinition.extension">
      <path value="MessageDefinition.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 resource. To make the use of extensions safe and manageable, there is a strict set of governance  applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension."/>
      <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="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"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="MessageDefinition.modifierExtension">
      <path value="MessageDefinition.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](http://build.fhir.org/extensibility.html#modifierExtension)."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="DomainResource.modifierExtension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Extension"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <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="false"/>
      <mapping>
        <identity value="rim"/>
        <map value="N/A"/>
      </mapping>
    </element>
    <element id="MessageDefinition.url">
      <path value="MessageDefinition.url"/>
      <short value="Business Identifier for a given MessageDefinition"/>
      <definition
                  value="The business identifier that is used to reference the MessageDefinition and *is* expected to be consistent from server to server."/>
      <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](http://build.fhir.org/resource.html#versions). 

In some cases, the resource can no longer be found at the stated url, but the url itself cannot change. Implementations can use the [meta.source](http://build.fhir.org/resource.html#meta) element to indicate where the current master source of the resource can be found."/>
      <requirements
                    value="Allows the message definition to be referenced by a single globally unique identifier."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.url"/>
        <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="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.url"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.identifier"/>
      </mapping>
    </element>
    <element id="MessageDefinition.identifier">
      <path value="MessageDefinition.identifier"/>
      <short value="Primary key for the message definition on a given server"/>
      <definition
                  value="A formal identifier that is used to identify this message definition 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 message definition 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 module."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.identifier"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.identifier"/>
      </mapping>
      <mapping>
        <identity value="objimpl"/>
        <map value="no-gen-base"/>
      </mapping>
    </element>
    <element id="MessageDefinition.version">
      <path value="MessageDefinition.version"/>
      <short value="Business version of the message definition"/>
      <definition
                  value="The identifier that is used to identify this version of the message definition when it is referenced in a specification, model, design or instance. This is an arbitrary value managed by the message definition 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 message definition 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 message definition with the format [url]|[version]."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.version"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.version"/>
      </mapping>
    </element>
    <element id="MessageDefinition.name">
      <path value="MessageDefinition.name"/>
      <short value="Name for this message definition (computer friendly)"/>
      <definition
                  value="A natural language name identifying the message definition. 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."/>
      <requirements value="Support human navigation and code generation."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.name"/>
        <min value="0"/>
        <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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="MessageDefinition.title">
      <path value="MessageDefinition.title"/>
      <short value="Name for this message definition (human friendly)"/>
      <definition
                  value="A short, descriptive, user-friendly title for the message definition."/>
      <comment
               value="This name does not need to be machine-processing friendly and may contain punctuation, white-space, etc."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.title"/>
      </mapping>
    </element>
    <element id="MessageDefinition.replaces">
      <path value="MessageDefinition.replaces"/>
      <short value="Takes the place of"/>
      <definition
                  value="A MessageDefinition that is superseded by this definition."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="MessageDefinition.replaces"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="canonical"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/MessageDefinition"/>
      </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="MessageDefinition.status">
      <path value="MessageDefinition.status"/>
      <short value="draft | active | retired | unknown"/>
      <definition
                  value="The status of this message definition. Enables tracking the life-cycle of the content."/>
      <comment
               value="Allows filtering of message definitions that are appropriate for use versus not."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.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="false"/>
      <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-snapshot1"/>
      </binding>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.status"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.status"/>
      </mapping>
    </element>
    <element id="MessageDefinition.experimental">
      <path value="MessageDefinition.experimental"/>
      <short value="For testing purposes, not real usage"/>
      <definition
                  value="A Boolean value to indicate that this message definition is authored for testing purposes (or education/evaluation/marketing) and is not intended to be used for genuine usage."/>
      <comment
               value="Allows filtering of message definitions 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 message definition."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.experimental"/>
        <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>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.experimental"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.class"/>
      </mapping>
    </element>
    <element id="MessageDefinition.date">
      <path value="MessageDefinition.date"/>
      <short value="Date last changed"/>
      <definition
                  value="The date  (and optionally time) when the message definition 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 message definition 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 message definition. 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="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.date"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.recorded"/>
      </mapping>
    </element>
    <element id="MessageDefinition.publisher">
      <path value="MessageDefinition.publisher"/>
      <short value="Name of the publisher (organization or individual)"/>
      <definition
                  value="The name of the organization or individual that published the message definition."/>
      <comment
               value="Usually an organization but may be an individual. The publisher (or steward) of the message definition is the organization or individual primarily responsible for the maintenance and upkeep of the message definition. 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 message definition. This item SHOULD be populated unless the information is available from context."/>
      <requirements
                    value="Helps establish the &quot;authority/credibility&quot; of the message definition.  May also allow for contact."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.publisher"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.witness"/>
      </mapping>
    </element>
    <element id="MessageDefinition.contact">
      <path value="MessageDefinition.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="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.contact"/>
      </mapping>
    </element>
    <element id="MessageDefinition.description">
      <path value="MessageDefinition.description"/>
      <short value="Natural language description of the message definition"/>
      <definition
                  value="A free text natural language description of the message definition from a consumer's perspective."/>
      <comment
               value="This description can be used to capture details such as why the message definition was built, comments about misuse, instructions for clinical use and interpretation, literature references, examples from the paper world, etc. It is not a rendering of the message definition 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 message definition is presumed to be the predominant language in the place the message definition was created)."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.description"/>
      </mapping>
    </element>
    <element id="MessageDefinition.useContext">
      <path value="MessageDefinition.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 message definition 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="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.useContext"/>
      </mapping>
    </element>
    <element id="MessageDefinition.jurisdiction">
      <path value="MessageDefinition.jurisdiction"/>
      <short
             value="Intended jurisdiction for message definition (if applicable)"/>
      <definition
                  value="A legal or geographic region in which the message definition is intended to be used."/>
      <comment
               value="It may be possible for the message definition to be used in jurisdictions other than those for which it was originally designed or intended."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="Jurisdiction"/>
        </extension>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/>
        </extension>
        <strength value="extensible"/>
        <description
                     value="Countries and regions within which this artifact is targeted for use."/>
        <valueSet value="http://hl7.org/fhir/ValueSet/jurisdiction"/>
      </binding>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.jurisdiction"/>
      </mapping>
    </element>
    <element id="MessageDefinition.purpose">
      <path value="MessageDefinition.purpose"/>
      <short value="Why this message definition is defined"/>
      <definition
                  value="Explanation of why this message definition is needed and why it has been designed as it has."/>
      <comment
               value="This element does not describe the usage of the message definition. 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 message definition."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.purpose"/>
      </mapping>
      <mapping>
        <identity value="w5"/>
        <map value="FiveWs.why[x]"/>
      </mapping>
      <mapping>
        <identity value="objimpl"/>
        <map value="no-gen-base"/>
      </mapping>
    </element>
    <element id="MessageDefinition.copyright">
      <path value="MessageDefinition.copyright"/>
      <short value="Use and/or publishing restrictions"/>
      <definition
                  value="A copyright statement relating to the message definition and/or its contents. Copyright statements are generally legal restrictions on the use and publishing of the message definition."/>
      <requirements
                    value="Consumers must be able to determine any legal restrictions on the use of the message definition and/or its content."/>
      <alias value="License"/>
      <alias value="Restrictions"/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.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="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
      <mapping>
        <identity value="workflow"/>
        <map value="Definition.copyright"/>
      </mapping>
      <mapping>
        <identity value="objimpl"/>
        <map value="no-gen-base"/>
      </mapping>
    </element>
    <element id="MessageDefinition.base">
      <path value="MessageDefinition.base"/>
      <short value="Definition this one is based on"/>
      <definition
                  value="The MessageDefinition that is the basis for the contents of this resource."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.base"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="canonical"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/MessageDefinition"/>
      </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="MessageDefinition.parent">
      <path value="MessageDefinition.parent"/>
      <short value="Protocol/workflow this is part of"/>
      <definition
                  value="Identifies a protocol or workflow that this MessageDefinition represents a step in."/>
      <comment
               value="It should be possible to use MessageDefinition to describe a message to be used by certain steps in a particular protocol as part of a PlanDefinition or ActivityDefinition."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="MessageDefinition.parent"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="canonical"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/ActivityDefinition"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/PlanDefinition"/>
      </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="MessageDefinition.event[x]">
      <path value="MessageDefinition.event[x]"/>
      <short value="Event code"/>
      <definition
                  value="Event code for messages conveying order-catalog content"/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.event[x]"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="Coding"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <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="MessageEvent"/>
        </extension>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/>
        </extension>
        <strength value="extensible"/>
        <description
                     value="message events for messages conveying order-catalog content"/>
        <valueSet
                  value="http://hl7.org/fhir/uv/order-catalog/ValueSet/catalog-message-events-vs"/>
      </binding>
    </element>
    <element id="MessageDefinition.category">
      <path value="MessageDefinition.category"/>
      <short value="consequence | currency | notification"/>
      <definition value="The impact of the content of the message."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.category"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="code"/>
      </type>
      <fixedCode value="consequence"/>
      <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="MessageSignificanceCategory"/>
        </extension>
        <strength value="required"/>
        <description value="The impact of the content of a message."/>
        <valueSet
                  value="http://hl7.org/fhir/ValueSet/message-significance-category|5.0.0-snapshot1"/>
      </binding>
    </element>
    <element id="MessageDefinition.focus">
      <path value="MessageDefinition.focus"/>
      <short value="Resource(s) that are the subject of the event"/>
      <definition
                  value="Identifies the resource (or resources) that are being addressed by the event.  For example, the Encounter for an admit message or two Account records for a merge."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="MessageDefinition.focus"/>
        <min value="0"/>
        <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>
      <constraint>
        <key value="md-1"/>
        <severity value="error"/>
        <human value="Max must be postive int or *"/>
        <expression value="max='*' or (max.toInteger() &gt; 0)"/>
        <xpath value="f:max/@value='*' or number(f:max/@value) &gt; 0"/>
        <source
                value="http://hl7.org/fhir/StructureDefinition/MessageDefinition"/>
      </constraint>
      <mustSupport value="false"/>
      <isModifier value="false"/>
      <isSummary value="true"/>
    </element>
    <element id="MessageDefinition.focus.id">
      <path value="MessageDefinition.focus.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="id"/>
        </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="MessageDefinition.focus.extension">
      <path value="MessageDefinition.focus.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="MessageDefinition.focus.modifierExtension">
      <path value="MessageDefinition.focus.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](http://build.fhir.org/extensibility.html#modifierExtension)."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <alias value="modifiers"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="BackboneElement.modifierExtension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Extension"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <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="MessageDefinition.focus.code">
      <path value="MessageDefinition.focus.code"/>
      <short value="Type of resource"/>
      <definition
                  value="The kind of resource that must be the focus for this message."/>
      <comment
               value="Multiple focuses addressing different resources may occasionally occur.  E.g. to link or unlink a resource from a particular account or encounter, etc."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.focus.code"/>
        <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="ResourceType"/>
        </extension>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/>
        </extension>
        <strength value="required"/>
        <description
                     value="One of the resource types defined as part of this version of FHIR."/>
        <valueSet
                  value="http://hl7.org/fhir/ValueSet/resource-types|5.0.0-snapshot1"/>
      </binding>
    </element>
    <element id="MessageDefinition.focus.profile">
      <path value="MessageDefinition.focus.profile"/>
      <short value="Profile that must be adhered to by focus"/>
      <definition
                  value="A profile that reflects constraints for the focal resource (and potentially for related resources)."/>
      <comment
               value="This should be present for most message definitions.  However, if the message focus is only a single resource and there is no need to include referenced resources or otherwise enforce the presence of particular elements, it can be omitted."/>
      <requirements
                    value="This profile allows setting boundaries for what content must appear within the message bundle vs. outside based on the declared aggregation constraints on referenced resources on this and related profiles."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.focus.profile"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="canonical"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/StructureDefinition"/>
      </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="MessageDefinition.focus.min">
      <path value="MessageDefinition.focus.min"/>
      <short value="Minimum number of focuses of this type"/>
      <definition
                  value="Identifies the minimum number of resources of this type that must be pointed to by a message in order for it to be valid against this MessageDefinition."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.focus.min"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="unsignedInt"/>
      </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="MessageDefinition.focus.max">
      <path value="MessageDefinition.focus.max"/>
      <short value="Maximum number of focuses of this type"/>
      <definition
                  value="Identifies the maximum number of resources of this type that must be pointed to by a message in order for it to be valid against this MessageDefinition."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.focus.max"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="string"/>
      </type>
      <condition value="md-1"/>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <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="MessageDefinition.responseRequired">
      <path value="MessageDefinition.responseRequired"/>
      <short value="always | on-error | never | on-success"/>
      <definition
                  value="Declare at a message definition level whether a response is required or only upon error or success, or never."/>
      <comment
               value="This enables the capability currently available through MSH-16 (Application Level acknowledgement) in HL7 Version 2 to declare at a message instance level whether a response is required or only upon error or success, or never."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.responseRequired"/>
        <min value="0"/>
        <max value="1"/>
      </base>
      <type>
        <code value="code"/>
      </type>
      <example>
        <label value="General"/>
        <valueCode value="always"/>
      </example>
      <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="messageheader-response-request"/>
        </extension>
        <strength value="required"/>
        <description
                     value="This enables the capability currently available through MSH-16 (Application Level acknowledgement) in HL7 Version 2 to declare at a message definition level whether a response is required or only upon error or success, or never."/>
        <valueSet
                  value="http://hl7.org/fhir/ValueSet/messageheader-response-request|5.0.0-snapshot1"/>
      </binding>
      <mapping>
        <identity value="v2"/>
        <map value="MSH-16"/>
      </mapping>
    </element>
    <element id="MessageDefinition.allowedResponse">
      <path value="MessageDefinition.allowedResponse"/>
      <short value="Responses to this message"/>
      <definition
                  value="Indicates what types of messages may be sent as an application-level response to this message."/>
      <comment
               value="This indicates an application level response to &quot;close&quot; a transaction implicit in a particular request message.  To define a complete workflow scenario, look to the [[PlanDefinition]] resource which allows the definition of complex orchestrations, conditionality, etc."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="MessageDefinition.allowedResponse"/>
        <min value="0"/>
        <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="false"/>
    </element>
    <element id="MessageDefinition.allowedResponse.id">
      <path value="MessageDefinition.allowedResponse.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="id"/>
        </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="MessageDefinition.allowedResponse.extension">
      <path value="MessageDefinition.allowedResponse.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="MessageDefinition.allowedResponse.modifierExtension">
      <path value="MessageDefinition.allowedResponse.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](http://build.fhir.org/extensibility.html#modifierExtension)."/>
      <alias value="extensions"/>
      <alias value="user content"/>
      <alias value="modifiers"/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="BackboneElement.modifierExtension"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="Extension"/>
      </type>
      <constraint>
        <key value="ele-1"/>
        <severity value="error"/>
        <human value="All FHIR elements must have a @value or children"/>
        <expression value="hasValue() or (children().count() &gt; id.count())"/>
        <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="MessageDefinition.allowedResponse.message">
      <path value="MessageDefinition.allowedResponse.message"/>
      <short value="Reference to allowed message definition response"/>
      <definition
                  value="A reference to the message definition that must be adhered to by this supported response."/>
      <min value="1"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.allowedResponse.message"/>
        <min value="1"/>
        <max value="1"/>
      </base>
      <type>
        <code value="canonical"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/MessageDefinition"/>
      </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="MessageDefinition.allowedResponse.situation">
      <path value="MessageDefinition.allowedResponse.situation"/>
      <short value="When should this response be used"/>
      <definition
                  value="Provides a description of the circumstances in which this response should be used (as opposed to one of the alternative responses)."/>
      <min value="0"/>
      <max value="1"/>
      <base>
        <path value="MessageDefinition.allowedResponse.situation"/>
        <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="false"/>
      <isModifier value="false"/>
      <isSummary value="false"/>
    </element>
    <element id="MessageDefinition.graph">
      <path value="MessageDefinition.graph"/>
      <short value="Canonical reference to a GraphDefinition"/>
      <definition
                  value="Canonical reference to a GraphDefinition. If a URL is provided, it is the canonical reference to a [GraphDefinition](http://build.fhir.org/graphdefinition.html) that it controls what resources are to be added to the bundle when building the document. The GraphDefinition can also specify profiles that apply to the various resources."/>
      <min value="0"/>
      <max value="*"/>
      <base>
        <path value="MessageDefinition.graph"/>
        <min value="0"/>
        <max value="*"/>
      </base>
      <type>
        <code value="canonical"/>
        <targetProfile
                       value="http://hl7.org/fhir/StructureDefinition/GraphDefinition"/>
      </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>
  </snapshot>
  <differential>
    <element id="MessageDefinition">
      <path value="MessageDefinition"/>
    </element>
    <element id="MessageDefinition.event[x]">
      <path value="MessageDefinition.event[x]"/>
      <short value="Event code"/>
      <definition
                  value="Event code for messages conveying order-catalog content"/>
      <type>
        <code value="Coding"/>
      </type>
      <mustSupport value="true"/>
      <binding>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName">
          <valueString value="MessageEvent"/>
        </extension>
        <extension
                   url="http://hl7.org/fhir/StructureDefinition/elementdefinition-isCommonBinding">
          <valueBoolean value="true"/>
        </extension>
        <strength value="extensible"/>
        <description
                     value="message events for messages conveying order-catalog content"/>
        <valueSet
                  value="http://hl7.org/fhir/uv/order-catalog/ValueSet/catalog-message-events-vs"/>
      </binding>
    </element>
    <element id="MessageDefinition.category">
      <path value="MessageDefinition.category"/>
      <fixedCode value="consequence"/>
    </element>
    <element id="MessageDefinition.responseRequired">
      <path value="MessageDefinition.responseRequired"/>
      <min value="1"/>
      <mustSupport value="true"/>
    </element>
  </differential>
</StructureDefinition>