NMRA conscripts

When the government decided to send conscripts overseas as reinforcements in late 1944, I have read somewhere that the nature of the NMRA reinforcement was to be "disguised" so that the receiving units would not be able to easily distinguish the NMRA man from a GS man.
Questions, first, can someone supply a source/sources that verify this practice?
Second, what steps were taken to "disguise" the NMRA men? (I believe new service numbers were issued?) Other steps? Sources for these changes?