6.5 Indicating unknown values

When the inclusion of a value is mandatory for a particular data element in the messages defined in this part of the AR standard, but a message sender cannot provide such data, the following values shall be entered:

• In cells where the data is meant to be a string: #unknown#;

• In cells where the data is meant to be a date: 9999-01-01;

• In cells where the data is meant to be a datetime: 9999-01-01T99:01:01; and

• In cells where the data is meant to be a duration: PT99H01M01S.

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