U2412M "b"

I have ordered a U2412M in december. It was ordered directly from dell. I have received the U2412Mb Rev 00. I have noticed online that there is a lot of talk about this "b" version and Rev 00. There is no definitive answer exactly what it means. I have seen Chris saying that b is the location, but I don't see how that has anything to do with it (b would be a version of some type if anything). It was also said that its best to buy it from dell directly. I did that. So what exactly is the status of these b and non b versions?