| Lingwa de Planeta | art-287 |
| twerde | |
| Sambahsa-mundialect | art-288 | kaurd |
| Deutsch | deu-000 | fest |
| Deutsch | deu-000 | hart |
| English | eng-000 | firm |
| English | eng-000 | hard |
| English | eng-000 | solid |
| Esperanto | epo-000 | dura |
| Esperanto | epo-000 | malmola |
| Nederlands | nld-000 | hard |
| Novial | nov-000 | solid |
| русский | rus-000 | жёсткий |
| русский | rus-000 | твёрдый |