| English | eng-000 |
| Middle Welsh | |
| ISO 639-3 | art-001 | wlm |
| ISO 639-PanLex | art-274 | wlm-000 |
| ISO 639-3 Inverted Names | art-291 | Welsh, Middle |
| brezhoneg | bre-000 | krenngembraeg |
| 普通话 | cmn-000 | 中古威尔士语 |
| 國語 | cmn-001 | 中古威爾斯語 |
| Cymraeg | cym-000 | Cymraeg Canol |
| Deutsch | deu-000 | Mittelwalisisch |
| suomi | fin-000 | keskikymri |
| français | fra-000 | moyen gallois |
| galego | glg-000 | Lingua galesa media |
| italiano | ita-000 | Medio gallese |
| italiano | ita-000 | medio gallese |
| 日本語 | jpn-000 | 中期ウェールズ語 |
| bokmål | nob-000 | mellomwalisisk |
| português | por-000 | galês médio |
| русский | rus-000 | Средневаллийский |
| русский | rus-000 | Средневаллийский язык |
| русский | rus-000 | средневаллийский |
| svenska | swe-000 | medelwalesiska |
| Cymraeg Canol | wlm-000 | Kymraec |