What does this mean?

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
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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.