I found the reviews for THE MUMMY on BLU-RAY

[Chad Varnadore]

Originally Posted by alphadec

why is it so difficult to let us know what region coding universal is using. ?

Probably because Universal doesn't list any region coding on the box. Since Universal supported HD DVD, region coding apparently isn't important to them. They may not be using it with BD either. Regardless, my understanding of BD spec is that region coding can't be used for catalog films like The Mummy. It was only implemented on BD for new films and there is only an option for the first year after the films debut, so that the home video release in one country doesn't infringe on theatrical exhibition in other parts of the world where the film may still be playing.