This paper presents the UZH Shared Task at the 13th Workshop on Argument Mining and Reasoning, co-located with ACL 2026, which focuses on reconstructing argumentative structure in highly formal legal-political texts, namely United Nations resolutions and recommendations. The shared task addresses the challenge of recovering paragraph-level reasoning patterns from the fairly formulaic structure of international decision-making records. It comprises two subtasks: (1) paragraph classification, where systems identify paragraph type (preambular or operative) and assign one or more thematic tags, and (2) argumentative relation prediction, where systems infer links between paragraphs and label them with relation types.