If it is bytes, then the programmer has reserved bits from M1150.0 to M1169.7 for global data tranfer.
If it's bits, then the programmer has reserved bits from M1150.0 to M1152.3 for global data transfer.
In the latter case, why would anyone do it that way? Cutting off the reservation half way through a byte?
PS. Electrician - not an engineer or programmer.