This highest Church court, which spurns modern rules of evidence, can hand down the final ruling on people's marriages. It functions as an appeal court for decisons of the Rota Romana which specialises in annulments. The judgements of the Signatura are upheld by the Austrian concordat.
(Latin: signatura apostolica)
This is the Vatican’s supreme court. The Apostolic Signatura is the court of last instance and therefore handles appeals against decisions of the Rota Romana, which is the Vatican's ordinary appeals court. Below these come the bishops’ tribunals which are “almost exclusively” devoted to marriage annulment. This is why the higher courts have to deal with “a significant number” of objections to the flood of annulments sought through the lower ones. The justices of all these ecclesiastical courts still wear the mediaeval legal hat which identifies John of Nepomuk, patron saint of lawyers. However, the judges in the higher courts, the Apostolic Signatura and the Rota Romana, are clothed in red, rather than black.
E.g. The Austrian Concordat (1933 Art. 7.4) recognises judgements of this court, rather than Austrian civil courts, as decisive for marriages celebrated in a Catholic church, regardless of the opinions of the participants.