G2PDT
 
     G2PDT can be used to specify any or all of the values in the Product 
     Definition Template (PDT), describing the grid in the output GRIB2 
     message.  This provides both a method of identifying a diagnostic grid, 
     when the standard table lookups will not suffice, as well as a means to 
     add supplemental information to the PDT.  If left blank, the PDT will be 
     filled in as much as pssible from the information in the grid file and 
     appropriate tables.
 
        PDT number | List of PDT values (each value separated by ;)
 
     The PDT number is the Product Definition Template number used to
     describe the grid.

     Users can set the value for each item of the appropriate PDT ( in the 
     same order as specified in the PDT ), and those values will overwrite
     any that were automatically generated from information in the gempak 
     grid file.