Removed:
"option96" => array ("FriendlyName" => "localeId", "Type" => "text", "Size" => "50", "Description" => "Locale to use in communications with the contact. The locale also decides which locale should be used on invoices to the contact. See https://dev.billysbilling.dk/api/v1/types/locales for possible values. This will be used for ALL contacts.", "Default" => "da_DK"),
Uses function countryId() to find the localId value.