| Bit Number | Value | Meaning |
| 1-2 | Reserved | |
| 3 | 0 1 | i direction increments not given i direction increments given |
| 4 | 0 1 | j direction increments not given j direction increments given |
| 5 | 0 1 | Resolved u- and v-components of vector quantities relative to easterly and northerly directions Resolved u- and v- components of vector quantities relative to the defined grid in the direction of increasing x and y (or i and j coordinates respectively |
| 6-8 | Reserved, set to 0 |