Three different groups of operators are distuingished in the PMB: identity operators, temporal operators, and spatial operators.
| Identity Operator | Identifier | Char | Meaning | Document |
|---|---|---|---|---|
| EQU | 700000011 | = | equal | 06/2903 |
| NEQ | 700000014 | ≠ | not equal | 00/1657 |
| APX | 700000013 | ≈ | approximately equal | 16/1892 |
| ANA | 700000012 | ≡ | anaphoric link | 06/1601 |
| LES | 700000006 | < | less than | 92/0875 |
| MOR | 700000010 | > | greater than | 01/3352 |
| TOP | 700000007 | ≤ | less or equal than | 68/2535 |
| BOT | 700000008 | ≥ | greater or equal than | 23/1853 |
| Temporal Operator | Identifier | Char | Meaning | Document |
| TPR | 700000001 | ≺ | temporal precedes ("before") | |
| TSU | 700000002 | ≻ | temporal succeeds ("after") | 00/1593 |
| TIN | 700000003 | ⊏ | temporal inclusion | |
| TCT | 700000004 | ⊐ | temporal contains | |
| TAB | 700000005 | ⋈ | temporal abuts ("meets") | |
| Spatial Operator | Identifier | Char | Meaning | Document |
| SXP | 700000015 | ≫ | spatial behind | |
| SXN | 700000016 | ≪ | spatial before | |
| SZN | 700000017 | ⊻ | spatial under | |
| SZP | 700000018 | ⋎ | spatial above | 02/0781 |
| STI | ⨃ | spatial topological inside | 05/1662 | |
| STO | ᑘ | spatial topological outside | 06/2541 | |
| SY1 | ∥ | spatial beside | 49/0046 | |
| SY2 | ⚮ | spatial between | ||
| SXY | ≖ | spatial around |