Section 0: INDICATOR SECTION
| Octets | Key | Type | Content |
| 1-4 | identifier | ascii | "GRIB" (coded according to the International Alphabet No. 5.) |
| 5-6 | reserved | unsigned | Reserved |
| 7 | discipline | codetable | Discipline - GRIB Master Table Number (see Code Table 0.0) |
| 8 | editionNumber | unsigned | GRIB Edition Number (currently 2) |
| 9-16 | totalLength | unsigned | Total length of GRIB message in octets (including Section 0) |