On Mon, 14 Sep 2009 15:06:20 +0100, tony sayer
wrote:


Http://www.telephonesuk.co.uk/wiring_info.htm

might help...


I'm afraid it doesn't. I had already found that site by google.
There's a lot of information there but all it says about the
green/white pair is:

"Terminal pins 1 and 6 may be absent on some versions of C/NTE5, but
these connections are not normally used anyway."

I notice all web sites say something similar "not normally used" but
they don't say "never used". This implies that occasionally they are
used but what for? And why do manufacturers spend money including them
if they don't have a use?

If I add any more extensions is it worth using 3-pair/6-core cable or
can I save some money by buying the 2-par cable?

Thanks.