| Coal rank | Abbreviation | % Carbon | % Hydrogen | % Oxygen |
| Lignite | BNK | 70 | 6 | 34 |
| Sub-bituminous coal | FLK | 75 | 6 | >9.8 |
| Gas flame coal* | WBF | 84 | 6.23 | 7.6 |
| Gas flame coal | WBS | 84 | 6.23 | 7.6 |
| Fat coal | SEC | 88 | 4.5 | 2.8 |
| Anthracite | - | 94 | 3 | 2 |