To define a language, choose Tools, Language, System Languages from the menu and create a record that contains the language name.
Language names are case-sensitive. You can name a language by any string, but it is good practice to use ISO 639-1 language codes, for example:
The advantage of ISO 639-1 language codes is that Internet software such as browsers may increasingly be able to offer additional functionality for the language automatically, for example spelling or translation help.
If you only want to deploy USoft in the factory English that it is shipped in, you do not need to define this language. But if you do not define English as a language, then you do not get the advantage of the ISO 639-1 code.
USoft-shipped message translations for Dutch
USoft 9.1 ships System Local Messages for the Dutch language, identified as "nl". You can load these by choosing Tools, Language, Load System Messages.