This read-only octet string (up to 32 characters) reports the operator-identifying trail trace text actually being received right now on an OTUC3 (300 Gb/s-class flexible OTU) trunk port. An administrator compares this live value against the configured expected operator string to confirm the incoming signal genuinely originates from the intended carrier's equipment. For example, if OTUC3 reports a received operator string that does not match the expected value, that discrepancy is treated as evidence of an unintended cross-connection to a different operator's network.