In the B+ position you should not rest on the non-standing foot, although I do it all the time!
I never heard the story about it being named after Mr. B.!!!! But think that's possible! All I know is that the Russians used this position before Balanchine was popular. Look at old videos! But it's still possible that Mr. B. popularized it the United States! I only met him three weeks before he died, and didn't have much time to talk about what he did for ballet!
balletboy[/i]