UTM Coordinate Systems
In the Assign Coordinate System dialog, the coordinate systems under Predefined are separated into different categories.
The UTM category contains different systems separated by country, region, or type. Coordinates are in meters. The difference between the systems are in the definition of the false easting, northing, central longitude, central latitude, standard parallel or datum. Settings are defined for specific regions or individual countries. Properties for each coordinate system and datum are listed in the dialog by clicking on the desired system.