Examples from "Localization" section of the form reference: form.error,form.error.l10n - Since the form is localized [form.error] is not read from schema apart if [form.error.l10n] is [true] - Submit an invalid date in all 3 controls to see the difference - In this case probably the default message is better Required [element], Single Occurrence, with Simple Type [inline-Form-Field] localName is [Field] without namespace Required [element], Single Occurrence, with Simple Type [inline-Form-FieldWithError] localName is [FieldWithError] without namespace Required [element], Single Occurrence, with Simple Type [inline-Form-FieldWithError2] localName is [FieldWithError2] without namespace Examples from "Localization" section of the form reference: form.error,form.error.l10n - Since the form is localized [form.error] is not read from schema apart if [form.error.l10n] is [true] - Submit an invalid date in all 3 controls to see the difference - In this case probably the default message is better