Mac Mini Audio out jack - s/pdif coaxial?

The MAC mini manual says " the headphone port is also a S/PDIF stereo 3.5 mini-phono jack".

So how do I hook up the MAC mini to my receiver's coaxial S/PDIF ports (standard RCA connector) - not optical Toslink ports.

Are there three choices:
1. stereo headphone (analog) output to analog input on receiver
2. optical Toslink S/PDIF via mini-Toslink adapter
3. mini 3.5mm S/PDIF jack to coaxial cable to RCA S/PDIF input (google search turned up a report this should be done with a monoaural 3.5mm jack)
see http://www.ramelectronics.net/html/RCA-mini-spdif.html

Or is option 3 a misunderstanding of the Apple manual?

Will plugging a mono jack into a stereo headphone jack short circuit the two audio channels or do some other damage?

The guys at the local Apple store didn't have a clue about coaxial s/pdif nor did Apple support by phone.

Thanks.