These constants are used to determine which language RDO should use when generating error messages.
| Constant | Value | Description |
| rdLocaleSystem | 0 | System |
| rdLocaleEnglish | 1 | English |
| rdLocaleFrench | 2 | French |
| rdLocaleGerman | 3 | German |
| rdLocaleItalian | 4 | Italian |
| rdLocaleJapanese | 5 | Japanese |
| rdLocaleSpanish | 6 | Spanish |
| rdLocaleChinese | 7 | Chinese |
| rdLocaleSimplifiedChinese | 8 | Simplified Chinese |
| rdLocaleKorean | 9 | Korean |