| Octet No. | Contents | 
|---|---|
| 10 | 
    Parameter category (see Code table 4.1) | 
    
| 11 | 
      Parameter number (see Code table 4.2) | 
    
| 12 | 
      	Type of wave period interval (see Code table 4.91) | 
    
| 13 | 
      	Scale factor of lower wave period limit | 
    
| 14-17 | 
      Scaled value of lower wave period limit (see Note 1) | 
    
| 18 | 
      	Scale factor of upper wave period limit | 
    
| 19-22 | 
      Scaled value of upper wave period limit (see Note 1) | 
    
| 23 | 
      Type of generating process (see Code table 4.3) | 
    
| 24 | 
      Background generating process identifier (defined by originating center) | 
    
| 25 | 
      Analysis or forecast generating process identifier (defined by originating center) | 
| 26-27 | 
      Hours of observational data cut-off after reference time (see Note 2) | 
    
| 28 | 
      Minutes of observational data cut-off after reference time | 
    
| 29 | 
      Indicator of unit of time range (see Code Table 4.4) | 
    
| 30-33 | 
      Forecast time in units defined by previous octet | 
    
| 34 | 
      Type of first fixed surface (see Code Table 4.5) | 
    
| 35 | 
      Scale factor of first fixed surface | 
    
| 36-39 | 
      Scaled value of first fixed surface | 
    
| 40 | 
      Type of second fixed surface (see Code Table 4.5) | 
    
| 41 | 
      Scale factor of second fixed surface | 
    
| 42-45 | 
      Scaled value of second fixed surface | 
    
| 46 | 
      Type ensemble forecast (see Code Table 4.6) | 
    
| 47 | 
      Perturbation number | 
    
| 48 | 
      Number of forecasts in ensemble | 
    
| Notes: (1) Wave periods should be specified in seconds (2) Hours greater than 65534 will be coded as 65534  |