| Locale::Constants | constants for Locale codes | 2.01 |
| Locale::Country | ISO codes for country identification (ISO 3166) | 2.06 |
| Locale::Currency | ISO three letter codes for currency identification (ISO 4217) | 2.02 |
| Locale::Language | ISO two letter codes for language identification (ISO 639) | 2.02 |
| Locale::Script | ISO codes for script identification (ISO 15924) | 2.02 |