| Code | Description | Comment | Version |
| A | Add ordered tests to the existing specimen | | from v2.1 |
| C | Cancel order for battery or tests named | deprecated | from v2.1, removed after v2.1 |
| G | Generated order; reflex order | | from v2.1 |
| L | Lab to obtain specimen from patient | | from v2.1 |
| O | Specimen obtained by service other than Lab | | from v2.1 |
| P | Pending specimen; Order sent prior to delivery | | from v2.1 |
| R | Revised order | | added v2.2 |
| S | Schedule the tests specified below | | from v2.1 |