+/- before the Memory Clock value indicates an offset memory clock. If it is simply the number, it indicates a locked memory clock.
Command Line Launch String:
Replace [Wallet] with your wallet address and [Worker] with your worker name
t-rex.exe -a autolykos2 -o stratum+tcp://ergo-us-west1.nanopool.org:11111 -u [Wallet] -w [Worker] -p x --lock_cclock 570 --mclock -500