The defective apparatus notice was introduced in EToN6. It follows the same principal as the unattributable works notice.
The authority will send a 1901 notice and the Utility will need to respond with acceptance or Rejection. (2000 or 2001)
If the works is accepted the utility must add a works reference to the ‘Actual Works ref’ field. If the user does not manually add one the system can generated a works and associate that works ref to this defective apparatus notice.
Authorities can only send these to one recipient at a time. So if a Utility reject it then the authority can use the same notice and send it to another authority and so on until it has been accepted.