Submitting new translations

Do not submit a translation for a language that already has an up-to-date translation unless you would like to become an official maintainer.
Any translation must be based on the English Default.isl translation file, therefore you should be able to read and understand English fairly well.
Please always try submitting a translation based on the most recent Default.isl.
Before you start translating, read the [LangOptions] section and [Messages] section topics in the Inno Setup help file.
When translating the text, do not add to or change the meaning of messages to suit your personal taste. For example, do not append "Try again one more time." to the end of an error message if it didn't say that already. All messages in your translation must be as close to the original English messages as possible.
Do not add your own custom messages to the [CustomMessages] section. Only translate the existing ones.
Add the English language name, your name and your e-mail address at the top of the translation file (as a comment).
Make sure the version number at the top of the translation file is up to date.
Make sure you use the correct LanguageID setting. See https://learn.microsoft.com/en-us/windows/win32/intl/language-identifier-constants-and-strings for a list of valid language IDs. If no language ID currently exists for your language, use zero.
Please use Windows-style line breaks (CR/LF) and not Unix-style line breaks (LF only).
Please use UTF-8 encoding without a BOM. LanguageCodePage should still always be set if possible.
Test your translation. It should not cause any errors or warnings when compiled by the Inno Setup compiler.
Attach your translation file to an e-mail to mlaan AT innosetup.nl. You may also submit your file via GitHub. See CONTRIBUTING.md on GitHub for more information.
Check that you attached the correct translation file.
Send the e-mail.

If you do not follow all of the above rules, your translation may be rejected without notice.

Note: if your translation is accepted but a new version of Inno Setup is released with a changed Default.isl and you didn't update your translation within 3 weeks' time after that release but someone has submitted an updated translation, your original translation might be replaced without notice.

To discuss your translation file or anything else related to translations, use the forum.

Official translations

As an official translator you will be required to quickly update translations once a change is announced to the istrans mailing list, otherwise your translation might lose official status without notice.

Official translation submission:

First get your translation accepted as an unofficial translation, as explained above.
Contact Martijn Laan requesting official status for your translation.
We will do a review, and once all findings are resolved, your translation will gain official status and be included in the Inno Setup installer. You'll also be invited to join the istrans mailing list.