According to Sheldon:
"It is customary to orient the rim so that the label is readable from the bicycle's right side. If the hub has a label running along the barrel, it should be located so that it can be read through the valve hole. These things will not affect the performance of the wheel, but good wheelbuilders pay attention to these things as a matter of pride and esthetics."
So, as long as you remember which way the label was oriented, it's okay to take it off. I guess you can also figure this out by the orientation of the eyelets adjacent to the valve hole.