When creating or editing a category, the default group names (everyone, admins, moderators, staff) should be translated. However, sometimes this is not the case:
1. Create a new category Test (without changing any permission):
Group name everyone (jeder) is translated in permission list.
Group names are not translated in group selection (e.g. staff should be Mitarbeiter).
2. Edit the created category Test
Group name everyone is not translated in permission list.
Group names are not translated in group selection, except everyone (jeder).
3. Set permissions explicitly
Same as 2.
PS: Interestingly, the trust_level group names are translated.