Yes, that is all. Just in case you don't fully understand, they mean only at one end. You can either reverse the speaker wires at the amplifier end, or at the speaker end (same result).
Connect my amp out of phase?
My new preamp, AES / Ary AE-3 DJH says "connect your amplifier out of phase when using this preamp. The output of the AE-3 is inverting. Connect your speaker wire out of phase (+) to (-) and (-) to (+)." Is the only thing that I need to connect differently, the speaker cable?