Examples from "Form Optional / Required" section of the form reference: convert whitespace only string value to {absent} with ctrl.emptyisnull=true Optional [element], Single Occurrence, with Simple Type [inline-Form-FieldStringOptionalEmptyIsNull] localName is [FieldStringOptionalEmptyIsNull] without namespace Required [element], Single Occurrence, with Simple Type [inline-Form-FieldStringRequiredEmptyIsNull] localName is [FieldStringRequiredEmptyIsNull] without namespace Examples from "Form Optional / Required" section of the form reference: convert whitespace only string value to {absent} with ctrl.emptyisnull=true