Regional restrictions now in the UK

[gazza]

I can add a bit to this from personal knowledge. Back in the sixties publishers had the world divided. Britain got the British Empire as constituted on January 1, 1947 with the exception of India which shall be considered an open territory. The United States got the US plus its possessions (which were too small to be relevant) and the rest of the world, including India, was open market.
Typically an American work -- it extended beyond books -- would not be published in Britain until well after, normally a year or so, the American edition. And vice versa.
There was an added feature that the paperback version of a book could only be published two years after the hardback.
These rules were very strictly kept to and it meant that authors lost money because their books were not available on the legitimate market. So there was a black market in illegally published books the sales from which the author saw not one cent or penny.
The basic idea to keep in mind is the publisher does not care in the slightest about the author. The money is for the publisher. The restrictions are ever and always to the benefit of the publisher. When publishers want to retain their total hold on a market they always quote the author not getting paid.
I am both a publisher and an author and I can tell you agreements are not signed with the author in mind. Many publishers now cut the author out of any royalty scheme whatsoever.

Gareth Powell in Sydney

[DawnFalcon]

And of course the UK had the Net Book Agreement for most of the last century...