Rear fog light ... one or two

[RivaRay]

When checking which bulbs needed to be replaced on my 07 XC90, I wondered who could have possibly stolen my rear right fog light wiring harness! LOL
... Then I came across this article which explains why vehicles have one rear fog light. Thought I'd share with others that wondered the same.

http://dastern.torque.net/Rearfogs/Rearfogs.html

[oragex]

There is indeed an empty socket on the right side - for right hand driving cars. But I think almost nobody knows about these rear fog lights, at least not how to 'interpret' them when seeing in real life situation