The way I read it there shouldn't have been any difference. 
 
It has always been my understanding that both optical and RCA type connections are S/PDIF but maybe I have that wrong?  TOSLINK is an official trademark held by Toshiba so if the connection is the standard EIAJ optical connection it may not be in their interest to use that terminology at all.  Futhermore I'd be surprised if the optical connection was not S/PDIF which from what I can tell has been an unofficial industry standard for quite a while, same for the RCA and XLR for that matter.  Heck, after a bit more research the only non-S/PDIF connection should be the USB so use of that term to describe only the RCA connection would be incorrect. 
 
As much as you loathe Wikipedia grawk, their article on S/PDIF is at least half decent.