It seems many very user-visible applications need to (directly or
indirectly) display output that come from PAM modules, such as the
login and "Password: " prompts, as far as I understand it.
This poses a big problem for internationalization, as this means that
untranslated English strings are being very prominently injected into
otherwise perfectly localized user interfaces.
As a consequence, it must be made possible to translate the strings
that PAM modules produce.
l10n will be supported by the next upstream PAM release.