I just changed "MGRS" to "USNG/MGRS" in the language
files, which will produce the correct USNG result in
most cases, but not in Europe and north. This is due
to MGRS using the NATO UTM grid numbering, whereas
USNG uses the regular 6 degree UTM grid numbering.
To be absolutely correct in all cases we'll need to
add USNG as a separate option in the Coordinates
configuration and add a new line to the Coordinate
Calculator for USNG, so that it uses the correct grid
numbering for any position in the world.
For operation anywhere than Europe/North of Europe
though, the current scheme implemented in software