In django the string "This field is required." gets translated to the german string "Dieses Feld ist zwingend erforderlich."

As soon as I add "rest_framework" to the settings.py the german string changes to "Dieses Feld ist erforderlich."

The german word "zwingend" is missing.

You don't need to understand the german words.

But why does this happen?

Here is the django po file translation:

https://github.com/django/django/blob/master/django/conf/locale/de/LC_MESSAGES/django.po#L611

Where does the other translation come from?

I could not find a po-file in the repo of django-rest-framework

Why does this sentence get translated twice? One time in django, one time in the rest-framework?