| 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 center) |
| 14 | Forecast generating processes identifier (defined by originating center) |
| 15-16 | Hours after reference time of data cutoff (see Note 1, below) |
| 17 | Minutes after reference time of 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 surface (see Code Table 4.5) |
| 30 | Scale factor of second fixed surface |
| 31-34 | Scaled value of second fixed surface |
| 35 | Type of ensemble forecast (ee Code Table 4.6) |
| 36 | Perturbation number |
| 37 | Number of forecasts in ensemble |