I'm guessing t's referring to a SpeakOn cable. Normally a SpeakOn is wired +1 -! at both ends of the cable for regular use. To run the amp in Bridge mode, if the amp has two power amps, it would be wired +1 -1 at the speaker cabinet end and +1 +2 for the amp..
BTW a SpeakOn cable is all you should use with a high power amp.