Kernrechtsfrage
Whether the appeal could challenge alleged violations of the Hague Service Convention and related treaty rules on service abroad
Extrahierter Entscheid
Yes, those treaty-law objections were admissible on appeal in this civil dispute, but any constitutional complaints were not.
Extrahierte Begründung
In a civil case, federal and treaty law may be reviewed on appeal; treaty-compliant service was a necessary preliminary issue for the cantonal default procedure and thus reviewable.