I think there's a difference between the English and the rest of GB. In my experience the English have been very strict rule followers. Here are just a couple of examples.
Once on a rainy morning at Worplesdon I was a single playing behind a two ball. We were the only players on the back 9 and I was on their tail the entire round. On a par 3 I asked if I could join them. They declined because the rule was only two ball play was allowed at that time. The time for 4 ball play was coming at the top of the hour about 15 minutes away, and there was no one behind us. They did let me play through though.
At Liphook I was required to replace my barely visible black below the ankle socks with white socks due to their white socks only rule when wearing shorts.
Stewart
You seem to be suggesting that in Scotland and presumably Wales and NI that it isn't like that. Can I suggest you try wearing anything but white socks with shorts at Glasgow, or try to play a fourball at Muirfield in the morning, or indeed wear stretch denim at Elie, and I think you'll find out that there are rules elsewhere in the UK.
Niall
White socks with shorts? HERESY!
Everyone knows that knee socks are the only appropriate pairing with shorts. A few years ago I went on a beautiful summer's day to Royal Cinque Ports to play golf. I wore shorts, and drove to Deal, and, on arrival, parked in the visitors' car lot. Literally the instant I switched off the engine I had a moment of clarity: "S***! It's a long sock club!" Obviously I was wearing white ankle socks. Andrew Reynolds, now sadly retired after 45 years as head pro at RCP, but shortly to take over as the club's captain, was delighted to relieve me of, I think, £25, for a pair of RCP knee socks. They're still in my sock drawer, I don't think I have worn them since. Actually it was one of Andrew's minions, but I'm sure the feeling was the same...