http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-templateExtractValue|4.0.0-ballot

Provides an expression to evaluate any value(s) to replace in the given template extraction context. If no result is evaluated, the element in the templated resource will be removed, and futher processing of it's children is not required.
element_idtypes
Extension
Extension.extension
Extension.url
Extension.value[x]
Extension
Extension.id
Extension.extension
Extension.url
Extension.value[x]