<status value="draft"/><experimental value="false"/><date value="2013-07-04"/><publisher value="HL7"/><contact><telecom><system value="url"/><value value="http://www.hl7.org"/></telecom></contact><description value="A unit that the user may choose when providing a quantity value."/><fhirVersion value="5.0.0"/><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="Questionnaire.item"/></context><context><type value="element"/><expression value="ElementDefinition"/></context><contextInvariant value="type='quantity'"/><type value="Extension"/><baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension"/><derivation value="constraint"/><snapshot><element id="Extension"><path value="Extension"/><short value="Unit choice"/><definition value="A unit that the user may choose when providing a quantity value."/><comment value="Provide either unitOption(s) or unitValueSet. If either of the extensions are present, the units for a Quantity element are constrained to only the units listed by the extensions - i.e. it is treated as a "required", not an "extensible" binding. In the absence of either, any unit is valid. See additional guidance and examples in the [SDC implementation guide](http://hl7.org/fhir/uv/sdc/behavior.html#unitOption). If this extension present and an answer is provided for the question item in the QuestionnaireResponse, then the valueQuantity **SHALL** have a Quantity.code and Quantity.system that match the Coding.code and system of one of the allowed values if the Coding has a code and/or system. If the Coding only has a display, then the Quantity.unit must match. (Note that Coding with only a display is strongly discouraged.) If there is a match on code and system, but no match on display/unit, systems MAY raise a warning. However, because of translation and bandwidth considerations, some systems **MAY** opt to drop the unit or express it in an alternate language."/><min value="0"/><max value="*"/><base><path value="Extension"/><min value="0"/><max value="*"/></base><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() > id.count())"/><source value="http://hl7.org/fhir/StructureDefinition/Element"/></constraint><constraint><key value="ext-1"/><severity value="error"/><human value="Must have either extensions or value[x], not both"/><expression value="extension.exists() != value.exists()"/><source value="http://hl7.org/fhir/StructureDefinition/Extension"/></constraint><isModifier value="false"/><mapping><identity value="rim"/><map value="N/A (MIF-level)"/></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"><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="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="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() > id.count())"/><source value="http://hl7.org/fhir/StructureDefinition/Element"/></constraint><constraint><key value="ext-1"/><severity value="error"/><human value="Must have either extensions or value[x], not both"/><expression value="extension.exists() != value.exists()"/><source value="http://hl7.org/fhir/StructureDefinition/Extension"/></constraint><isModifier value="false"/><isSummary value="false"/></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"><valueUrl value="uri"/></extension><code value="http://hl7.org/fhirpath/System.String"/></type><fixedUri value="http://hl7.org/fhir/StructureDefinition/questionnaire-unitOption"/><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](extensibility.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="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() > id.count())"/><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="Unit choice"/><definition value="A unit that the user may choose when providing a quantity value."/><comment value="Provide either unitOption(s) or unitValueSet. If either of the extensions are present, the units for a Quantity element are constrained to only the units listed by the extensions - i.e. it is treated as a "required", not an "extensible" binding. In the absence of either, any unit is valid. See additional guidance and examples in the [SDC implementation guide](http://hl7.org/fhir/uv/sdc/behavior.html#unitOption). If this extension present and an answer is provided for the question item in the QuestionnaireResponse, then the valueQuantity **SHALL** have a Quantity.code and Quantity.system that match the Coding.code and system of one of the allowed values if the Coding has a code and/or system. If the Coding only has a display, then the Quantity.unit must match. (Note that Coding with only a display is strongly discouraged.) If there is a match on code and system, but no match on display/unit, systems MAY raise a warning. However, because of translation and bandwidth considerations, some systems **MAY** opt to drop the unit or express it in an alternate language."/><min value="0"/><max value="*"/><mapping><identity value="rim"/><map value="N/A (MIF-level)"/></mapping></element><element id="Extension.extension"><path value="Extension.extension"/><max value="0"/></element><element id="Extension.url"><path value="Extension.url"/><fixedUri value="http://hl7.org/fhir/StructureDefinition/questionnaire-unitOption"/></element><element id="Extension.value[x]"><path value="Extension.value[x]"/><min value="1"/><type><code value="Coding"/></type></element></differential></StructureDefinition>