This read-only octet string (up to 15 characters) holds the Destination Access Point Identifier (DAPI) that an OTUC3 (300 Gb/s-class flexible OTU) trunk port is configured to expect in the incoming trail trace overhead. An administrator relies on this to confirm the near end has been provisioned with the correct expected destination identifier, so an unexpected DAPI in the received trace reliably indicates a misrouted or misconnected fiber. For example, if this expected DAPI is set to 'SITE-B-RX' but the receiving OTUC3 facility instead sees a different destination string, that mismatch is the clue that traffic was patched to the wrong far-end node.