G2IS
 
     G2IS is a list of integers that are encoded into the GRIB2 
     Indicator Section ( Section 0 ) that identify the discipline
     and version of the GRIB2 message:
 
        Discipline ; version
 
     The discipline is an integer value identifying the all the products in
     the GRIB2 message and corresponds to GRIB2 Code Table 0.0:
              0  = Meteorological products  (default)
              1  = Hydrological products 
              2  = Land surface products 
              3  = Space products
              10 = Oceanographic products

     Note: Setting the discipline here will overwrite the discipline value
     obtained from the GRIB2 parameter tables.  Use only if you know the 
     requested grid is not in the tables.  (e.g. a diagnostic grid )

     The GRIB code form version recognized by program gdgrib2 is only
     version 2.  2 is currently the only valid entry for this field.