http://hl7.org/fhir/StructureDefinition/quantity-precision|5.2.0

Explicit precision of the number. This is the number of significant decimal places after the decimal point, irrespective of how many are actually present in the explicitly represented decimal.
typedestination
baseDefinitionhttp://hl7.org/fhir/StructureDefinition/Extension
typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/integer