| Type | Length | Values |
| 0x0 | Organization Unique Identifier (OUI) |
| 0x1 | Predictor type 1 |
| 0x2 | Predictor type 2 |
| 0x3 | Puddle Jumper |
| 0x10 | Hewlett-Packard packet-by-packet compression (PPC) |
| 0x11 | Stac Electronics LZS |
| 0x12 | Microsoft PPC |
| 0x13 | Gandalf FZA |
| 0x14 | V.42bis compression |
| 0x15 | BSD LZW compression |