It's a stereo digital port. The data is transferred like it would be across a network, without being converted back to an analog audio signal.
The Behringer 802 has it not, as your chuckle indicates you already suspect. The Johnson J-Station do; most DAT recorders and MiniDisc recorders do; the new Roland moceling mic preamp do; many other things do...
Great headroom,S/N ratio,no AD/DA losses.I have the j-station,my only piece of gear with S/PDIF and it sounds much better that way than using the 1/4 outs.
What you NEED to implement this kind of transfer are three things.
1) a device capable of sending S/PDIF (recorders/mixers/effects boxes/pres/generally any device that outputs or inputs at line level includes or has some competitive device that includes a digital output in either coaxial or optical S/PDIF or AES/EBU)
2) a device capable of receiving S/PDIF (same sort of stuff)
Both of them compatible as to type and capable of sending (or at least set to send at) the same sample size and sample rate. There are converters that bridge this gap but that's a last resort. Don't design extra crap into your chain.
3) an appropriate cable. Either optical if required or a video cable that looks like an ordinary mono RCA cable but isn't.
Or an AES/EBU cable which looks like an XLR mic cable.
BTW: my pre sounds better when I use the digital outs....