Official talk:Translation Howto
Part Two: Translating other parts of Scribus…
Translating the Render Frame Editor…
Translating Qt framework
Scribus is based on the Qt Framework and therefore some basic dialog box receive translations from the Qt directly. Ideally Qt framework would have complete translations on that specific relevant language.
But sometimes if we encounter using Scribus in another language besides english that:
- some basic dialog boxes appear English
- the specific language you are using in Scribus has been translated totally or that you've looked in the .ts file and can't find those non-translated strings
This indicates that the issue is an upstream Qt translation problem. To check this you can check the Qt translation state for your specific language here. The Qt framework is translated code.qt.io/cgit/qt/qttranslations, and this is the official guide for translators.
FYI, for those of you who are wondering why we don't just translate these Qt translated dependant strings directly in Scribus, see jghali's explanation.