This CoriantTypesEnableSwitch (default enabled) turns preemphasis of the transmitted signal on or off for the coherent optical channel (och-os) on the line side of a pluggable transceiver, a technique that boosts parts of the transmit signal to compensate for expected impairments before they occur. An administrator would disable this only in unusual circumstances, since preemphasis is normally left on to give the transmitted signal the best chance of being cleanly recovered at the far end. For example, an administrator would normally leave preemphasis enabled on och-os and only investigate disabling it if the far end reported unexpected signal quality after an optics or firmware change.