Nx3 stores the settings in a new manner compared to the previous versions.
The program now store only the settings that the costumer modify, so You cannot see all the old variables with the explainations as in old metric.def (or english.def), but only these affected by Your specific settings.
You can find the costumer defaults in a xml file located in:
C:\Documents and Settings\**YOUR USER HERE**\Local Settings\Application Data\Unigraphics Solutions\NX\
inside nx3_user.dpv (open with notepad)