| English | eng-000 |
| optionally | |
| العربية | arb-000 | باختيار |
| Universal Networking Language | art-253 | optionally(icl>how,ant>obligatorily,com>optional) |
| বাংলা | ben-000 | ঐচ্ছিকভাবে |
| bălgarski ezik | bul-001 | dobrovolen |
| català | cat-000 | opcionalment |
| čeština | ces-000 | volitelně |
| 普通话 | cmn-000 | 可选择地 |
| 普通话 | cmn-000 | 随意地 |
| 國語 | cmn-001 | 隨意地 |
| dansk | dan-000 | frivillig |
| Deutsch | deu-000 | freiwillig |
| Deutsch | deu-000 | optional |
| Deutsch | deu-000 | wahlweise |
| eesti | ekk-000 | valikuliselt |
| ελληνικά | ell-000 | προαιρετικά |
| Ellinika | ell-003 | ethelontikós |
| Ellinika | ell-003 | proairetikós |
| English | eng-000 | unsolicited |
| English | eng-000 | voluntarily |
| English | eng-000 | voluntary |
| Esperanto | epo-000 | libervola |
| Esperanto | epo-000 | nedeviga |
| Esperanto | epo-000 | propravola |
| suomi | fin-000 | valinnaisesti |
| suomi | fin-000 | vapaaehtoinen |
| français | fra-000 | bénévole |
| français | fra-000 | bénévolement |
| français | fra-000 | de son plein gré |
| français | fra-000 | facultatif |
| français | fra-000 | optionnellement |
| français | fra-000 | spontané |
| français | fra-000 | volontaire |
| hrvatski | hrv-000 | opcionalno |
| magyar | hun-000 | önként |
| magyar | hun-000 | önkéntes |
| íslenska | isl-000 | sjálfviljugur |
| italiano | ita-000 | facoltativamente |
| italiano | ita-000 | opzionalmente |
| italiano | ita-000 | spontaneo |
| italiano | ita-000 | volontariamente |
| italiano | ita-000 | volontario |
| 日本語 | jpn-000 | 任意に |
| 日本語 | jpn-000 | 随意に |
| にほんご | jpn-002 | ずいいに |
| にほんご | jpn-002 | にんいに |
| latine | lat-000 | automatus |
| latine | lat-000 | voluntarius |
| Nederlands | nld-000 | vrijwillig |
| bokmål | nob-000 | frivillig |
| bokmål | nob-000 | godvillig |
| polski | pol-000 | dobrowolnie |
| polski | pol-000 | dobrowolny |
| polski | pol-000 | ochotniczo |
| polski | pol-000 | ochotniczy |
| português | por-000 | espontaneamente |
| português | por-000 | livremente |
| português | por-000 | opcionalmente |
| português | por-000 | voluntário |
| română | ron-000 | facultativ |
| română | ron-000 | opțional |
| română | ron-000 | voluntar |
| русский | rus-000 | необязательно |
| русский | rus-000 | опционально |
| русский | rus-000 | по выбору |
| русский | rus-000 | факультативно |
| russkij | rus-001 | dobrowol'no |
| russkij | rus-001 | dobrowol'nyj |
| slovenčina | slk-000 | dobrovoľný |
| español | spa-000 | a voluntad |
| español | spa-000 | opcionalmente |
| español | spa-000 | voluntariamente |
| español | spa-000 | voluntario |
| svenska | swe-000 | fakultativt |
| svenska | swe-000 | frivillig |
| svenska | swe-000 | frivilligt |
| svenska | swe-000 | valfritt |
| Türkçe | tur-000 | gönüllü |