Art. 53 APA from 2022

Art. 53 III. Supplementary appeal petition
If the unusual complexity or special difficulty of an appeal case so requires, the appellate authority shall grant an appellant who so requests in his otherwise properly filed appeal a suitable additional period within which to supplement his grounds of appeal; in such cases, Article 32 paragraph 2 does not apply.
Es besteht kein Anspruch auf Aktualität und Vollständigkeit/Richtigkeit.