| Permitted value | Language | Designation | Definition |
|---|---|---|---|
| 4th edition | EN | 4th ed. (used since 2011) | 4th ed. (used since 2011) |
| 3rd edition | EN | 3rd ed. (2001-2010) | 3rd ed. (2001-2010) |
| 2nd edition | EN | 2nd ed. (1991-2000) | 2nd ed. (1991-2000) |
| 1st edition | EN | 1st ed. (1979-1990) | 1st ed. (1979-1990) |
| Not known | EN | Edition not known | It is not known which edition was used |