To be honest, I'm not sure how the various professional bodies and IEE committees get things changed. It's something I've never really looked into that closely. I'll have a look at the IEE website later.
Regarding the circuit arrangements for radial branches, there's nothing to stop anyone installing dedicated branches for anything, and I've often changed a washer/dryer etc. outlet during other work. In some cases it can be done quite easily from the attic or crawl space without having to tear up walls.
The rules about what outlets are permitted on radials have changed quite a bit over the years, but the current specs. are here:
www.tlc-direct.co.uk/Book/6.3.3.htm
