I'm surprised: the cable I bought was being sold as an "extension cable", and was labelled that way on the box. I'd expect that a cable intended to be cut into two would have twisted the leads so each distinct pin would have the same colour wire going to it.
Interestingly, if I'm wrong, then others are as well:http://www.alibaba.com/product-gs/516251450/SAE_2_Pin_Extension.htmlhttp://www.amazon.com/Hopkins-47965-2-Pole-Flat-Extension/dp/B0002Q80RW
I'm learning way more in this thread than I though! :-)
As for caravan vs trailer - I understand these kinds of cables are used more for the type of vehicle that tows boats, rather than rooms in which to camp. I'd call that a boat trailer - not sure what others would :-)