There appear to be two kernels, "OC0" (default), and "OC1" (overclock). This appears to be the names for the kernels.
However, the command-line syntax stated above is as I replied a few posts earlier, a space-delineated series of "1" or "0".
I just re-launched one of my rigs with the command line "miner -a 125_4 --OC1". It launched with no problem. There was no notice printed to the console as to the activation of an overclock kernel as the miner was launched. The hash rate is no different by any significant margin. The miner is steady with no rejects.
If there is an improvement for kernel "OC1", it is small. --scryptr
P.S. Just read your post above. Perhaps there is no kernel for my 1060 3GB. --scryptr
Currently only GTX1070 and GTX1080TI has OC1 kernel on BeamHashII algorithm