Prep Code That Establishes UPR -- The prep code that establishes UPR mode (either IPR or MMPR) for this machine (usually 95). If this machine has only inverse time feed available, or if neither IPR nor MMPR are available, enter NA (not available). If the prep code is not available, the postprocessor converts the feedrate to the appropriate feedrate code required by the machine. (Intcom 509)