Accuphase HS-Link

I have been reading that some of the Accuphase SACD players can process 176.4 kHz and 192 kHz through the HS-Link which I understand is some type of CAT 5 wiring. How would this work? Is it only for use with other Accuphase products? There is not really an explanation on the website.
It is proprietary to Accuphase, just as Denon-Link is proprietary to Denon. HDMI will do this, too. ;-)