OM

 Projection     : Oblique Mercator
 Also known as  : Oblique Cylindrical, Orthomorphic, or Hotine
 General class  : cylindrical
 Characteristics: conformal
 Earth model    : ellipsoid or sphere

Defining the MAPUNITS (Format A or B):

 MapUnits "om"      ! Standard name
 MapUnits "om e0"   ! Standard name and ellipsoid

Other parameters (Format A):

 TrueOriginLatitude "latitude_of_origin"      ! Required, for True origin
 FalseEasting       "false_easting"           ! Optional, default is zero
 FalseNorthing      "false_northing"          ! Optional, default is zero
 Scale              "scale_at_center"         ! Optional, default is one
 Point1Longitude    "longitude_central_line"  ! Required
 Point1Latitude     "latitude_central_line"   ! Required
 Point2Longitude    "longitude_central_line"  ! Required
 Point2Latitude     "latitude_central_line"   ! Required

Other parameters (Format B):

 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
 Scale               "scale_at_center"        ! Optional, default is one
 Azimuth             "azimuth"                ! Required, azimuth east of 
                                              !    north for central line

Possible errors:

 E100, "Invalid data" - In initializing for the projection, there 
        was an input data error
 E334, "Point cannot be projected" - In converting from geographic 
        coordinates to projection coordinates, the point projects 
        into infinity