SG

 Projection     : Stereographic
 General class  : azimuthal
 Characteristics: conformal
 Earth model    : sphere

Defining the MAPUNITS:

 MapUnits "sg"       ! Standard name
 MapUnits "sg e19"   ! Standard name and ellipsoid

Other parameters:

 TrueOriginLongitude "longitude_of_origin"  ! Required, for True origin
 TrueOriginLatitude  "latitude_of_origin"   ! Required, for True origin
 FalseEasting        "false_easting"        ! Optional, default is zero
 FalseNorthing       "false_northing"       ! Optional, default is zero

Possible errors:

 E334, "Point cannot be projected" - In converting from geographic 
        coordinates to projection coordinates, the point projects 
        into infinity