When the Message Sender is required to provide a data element but cannot do so, the following values shall be entered:

  1. In fields of type xs:string: “#unknown#” ;
  2. In fields of type xd:date: “9999-01-01”;
  3. In fields of type xs:datetime: “9999-01-01T99:01:01”; and
  4. In fields of type xs:duration: “PT99H01M01S”.

The circumstances under which such behaviour is permissible may be limited in the specific business relationship between message sender and message recipient.