US and Canada are region 1 - Britain is part of region 2. So, unless you have a DVD player that can change regions (many DVD drives are (via their software), many stand alone DVD players are not), buying out of your region means those DVDs are unplayable. You have to be careful.
Thanks for the information, MB. I didn't know for sure (or remember) if the Brits' DVDs were a different region code or not. I remembered that their videos are different.
My experience was so weird taking a surprising twist today.
The DVD I mentioned, the "Nicholas Nickleby" that aired on Bravo a couple of years ago but was a British production, had the number "4" on the back alongside the "DVD" and "Dolby Digital" logos. When I looked that up on the chart you provided a link to, it showed region 4 as being Australia, New Zealand, and Mexico. That seemed really weird. I bought the DVD as soon as it came out (shortly after the Bravo airing) directly from Acorn media. The Acorn information on the package showed a US address, so that was really confusing. As I mentioned, when I put the DVD into the drive, it was really, really loud and I didn't dare play it.
Now today I was looking up some movies on the Internet. Suddenly I saw the numeral "4" on a website. Something looked very familiar with that "4". Excited, I got out the "Nicholas Nickleby" DVD and compared the "4" on the package with the "4" on the webpage. It was the same design. Apparently, the "4" does not signify "Region 4" after all, but "Channel 4," a Brit network (I gather), which (I gather) must have been the film producer!
So I will be able to play it after all, but I still don't know what the loud noise like an airplane taking off was all about. I don't think it was my imagination.
(BTW, I also have the DVD of the 2002 or -03 Douglas Magrath version of "Nickleby". It's a charming confection with gorgeous scenery, Nathan Lane and Jamie Bell among the cast, but it's much more sugar-coated -- and abbreviated.)