It is odd. Just when you think you knew everything…, I did read that the B is an H, but the Bm is a B. So I guess when you're in Germany and they say they are playing in B, you better know this or else you may be off key I don't know. I am going to try this out someday and tell everyone we are playing in H, see what they say.
The Story has it that a composer a couple hundred years ago mistakenly put an H instead of a B, and because of this typo, that is how this all got started. I even read where someone from Norway said they use H instead of B there too. I don't know if this is standard practice in those countries or a select few who really use it? Fact, a more far fetched story has it that this is what Bach used for his famous BACH arrangements (that seems a little out there). I am not a classical guy so I don't know much about Bach other than his namesake.