[Dave Moll]

I too tend to use four-pair cabling a lot of the time - with double sockets for two extensions on a PBX. For completeness, a fifth pair uses slate (grey) with white. This convention can be extended to a maximum of thirty pairs by cycling through the blue to slate described above with first white, then red, black, yellow, violet and pink. With these multi-pair configurations it is really helpful to stick to a convention.

The point I was picking up in the earlier post was the reference to blue with white on pin 3 and orange with white on pin 5, which I would find very confusing.