PC

 Projection     : Polyconic
 General class  : conic
 Characteristics: neither conformal nor equal-area
 Earth model    : ellipsoid or sphere

Defining the MAPUNITS:

Projections such as TM or PC that have specific parameters cannot be defined using their generic name (for example, "PC D000") because this string does not define the projection completely. There may be any number of origins or false east/west for the same projection, depending on your location. The user is advised to include the specifics of the projection (True Origin, False Easting and Northing, and scale) by adding a new projection to the 'userproj.txt' file located in the $PROHOME/etc directory, and using this new ProjectionName string to define the MAPUNITS parameter.

Other parameters:

 TrueOriginLongitude "central_meridian"    ! 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