Have a look through the electrical sections on this DIY site: http://www.diydoctor.org.uk/home.htm
Just a couple of things to start the ball rolling:
A general rule for a ring main is that if you only have two cables in the back of an existing socket then it is ok to spur.
Have they not heard that in earlier versions of the IEE Regs. it was permissible to run two
outlets as a spur from a ring? Finding two cables into a socket does not
guarantee that it is part of the ring and therefore O.K. to spur from.
However, if you have a radial circuit with two cables coming in and out, this may be the last socket on that circuit and already has a spur.
Huh? How can you have a spur from the end of a radial circuit? If you add an outlet onto the end of a radial, the original outlet is no longer the end -- The new socket is!
The earth, or ground in America, in electrical terms, carries no current, and it is this that electricity will make a dash for when it is allowed to escape from its secure home in an electric cable or flex. This is because the earth has enough capacity to accept it and is not full up with electricity already. Should any fault develop in an electrical system the electricity will always head for earth, taking the easiest route there.
No, no, no, no, no, no, no...........
Is it any wonder that that earthing is so misunderstood when misinformation like this is perpetuated so often?