| Octet No. | Contents | 
    
      | 10 | Parameter category (see Code Table 4.1) | 
    
      | 11 | Parameter number (see Code Table 4.2) | 
    
      | 12 | Type of generating process (see Code Table 4.3) | 
    
      | 13 
 | Background generating process
identifier (defined by originating centre) 
 | 
    
      | 14 
 | Forecast generating process identified
      (see Code ON388 Table A) 
 | 
    
      | 15-16 
 | Hours after reference time data
cutoff (see Note 1) 
 | 
    
      | 17 
 | Minutes after reference time
data cutoff 
 | 
    
      | 18 
 | Indicator of unit of time range (see Code Table 4.4) 
 | 
    
      | 19-22 
 | Forecast time in units defined
by octet 18 
 | 
    
      | 23 | Type of first fixed surface (see Code Table 4.5) | 
    
      | 24 
 | Scale factor of first fixed
surface | 
    
      | 25-28 
 | Scaled value of first fixed
surface 
 | 
    
      | 29 | Type of second fixed surfaced (see Code  Table 4.5) | 
    
      | 30 
 | Scale factor of second fixed
surface 
 | 
    
      | 31-34 
 | Scaled value of second fixed
surfaces 
 | 
    
      | 35 
 | Percentile value (from 100% to
0%) 
 |