This read-only octet string (up to 32 characters) reports the operator-identifying trail trace text that an OTUC3 (300 Gb/s-class flexible OTU) trunk port is currently transmitting toward the far end. An administrator checks this to confirm the local node is advertising the correct operator string, which matters when several operators' equipment shares infrastructure and trace text is used to police misconnections. For example, reading this transmitted operator string on OTUC3 lets staff confirm it still reads the expected carrier name after a configuration change, rather than having reverted to a factory default.