What does this mean?

I suspect that you are not missing anything, someone else may be though. I believe it takes 3 wire to be balanced.

You are correct to be confused -- RCA connections are NOT balanced -- they are single-ended, unbalanced connections. In audio systems, balanced connections require XLR connectors.

From the ungodly, perverted vivisection on the Island of Dr. Moreau, could it be a balanced interconnect reterminated with RCA plugs?

ah Jameswei! You may have it!
I'll take a set.

Or, do you take the extra wire and plug it into the wall receptacle?

It simply means that one end of the cable weighs the same as the other end. If you coil it up and heave it into the woods, it will spiral gracefully into the void. Which is probably what you should do with such a confused cable. :-)
I'd try another seller, myself.
Still unbalanced,
Ed

Euro balanced interfaces sometimes use RCA's; 1 cable for inverting & another cable for non-inverting. Take a look at an Electrocompaniet component for an example of this approach.

This simply means that the cable has three conductors inside even though it has RCA's on the end. It has two conductors and a shield. The cable can easily be made fully balanced by replacing the RCA's with XLR's. All one has to do is solder the red wire to pin two the black wire to pin three and the shield to pin one. Or, for Europeans use the black wire for pin two and the red wire for pin three.

Bob and RW, thanks for bringing those points up. I wasn't familiar with how some EC gear was set up nor did i know about the European color codes. You both taught me something today : )

I know that the Goertz micropurl IC's make use of three conductors. If running balanced, all three are used. If running RCA's, the center "foil" is simply left floating. They do this in order to reduce capacitance, which can play havoc with line level components. Sean
>

Most High quality interconnects do have three conductors and it's only a matter of installing XLR's to use them in a balanced system.

Another item of importance is that the sheild should not be connected at one end and not the other. This can make the cable act as an RF antenna.

Rwwear has it right. Audioquest could be the culprit of the confusion (no offense to AQ--I do like their cables), but they did a long line of "triple balanced, RCA or XLR connections" they also had a previous line of "double balanced" Then they changed to calling them "X3" version rather than triple balanced, probably due to this confusion. The balanced aspect referred to the wire. But as stated to get true balanced functionality you need the XLR connection.

well almost right---
shields are terminated at the signal-originating end only to prevent ground loops. If terminated at both ends the shielding effect is degraded significantly.

Not True. If you are not going to terminate the sheild at both ends you shouldn't terminate it at either in an unbalanced system. This doesn't mean that you will automatically have RF problems if you do not comply with this rule, but you can.