| Value | Description | Notes | Issue number | Modified in Issue |
|---|---|---|---|---|
| 00 | Units | The quantity refers to a unit implied by the quantity type | 9 | |
| 07 | Days | 20 | ||
| 08 | Weeks | 9 | ||
| 09 | Months | 9 | ||
| 10 | Years | 20 | ||
| 20 | Classes | Multiple copies or units suitable for a class. A ‘class’ is a group of learners attending a specific course or lesson and generally taught as a group | 61 |