There are 16 units symbols recognized by this program.

 They are:

 SYMBOL    UNITS

   A       Angstroms
   nm      Nanometers
 um or u   Micrometers or Microns
   mm      Millimeters
   cm      Centimeters
   in      Inches
   ft      Feet
   yd      Yards
   m       Meters
   km      Kilometers
   mi      Miles (Statute)
   nmi     Nautical miles
   LS      Light Seconds
   AU      Astronomical Units
   LY      Light Years (Based on Julian year of 365.25 days)
   pc      Parsecs