Has anyone heard of composite cable, 14 and 12 awg in one cable?

I found this from Okonite, maybe this is it?
http://www.okonite.com/Product_Catalog/section7/sheet1.html

You may want to check with Clifford of Vermont. They specialize in unusual cables and even make special assemblies. Their number is 800-451-4381.

I have seen SJOW cords made up this way for pool lights. They use a 12ga ground and 14 ga circuit conductors.

We used to get composite cable for motor circuits from Houston Wire and Cable. Try this,(cat.# HW155 12014)it has 3 #12's and 4 #14's

http://www.houwire.com/products/products46.asp