This read-only octet string (up to 15 characters) reports the Destination Access Point Identifier that an OTUC3 (300 Gb/s-class flexible OTU) trunk port is actually transmitting toward the far end. An administrator checks this to confirm the local node is sending the DAPI string the remote site expects, which helps when a far-end trace mismatch needs to be traced back to a local provisioning error. For example, comparing this transmitted DAPI value on OTUC3 against the far end's expected-DAPI setting can quickly confirm whether both sides agree on the identifier before assuming a fiber patching mistake.