<![CDATA[This study examines the Tutup Uban tradition among the Malay community of Bulik District, Lamandau Regency, Central Kalimantan, by distinguishing its customary authority from its status under Indonesian marriage law. The study uses an exploratory qualitative socio-legal case design that combines semi-structured interviews with a customary leader and a participant who experienced the practice, field observation, and doctrinal analysis of primary marriage-law materials. Empirical data were analyzed thematically, while legal materials were examined to distinguish religious validity, administrative registration, and customary recognition. The findings show that Tutup Uban is understood by the two informants as a symbolic practice performed when a younger sibling marries before an unmarried older sibling. Its principal functions are to express respect, maintain family relationships, and obtain social acceptance through symbolic gifts and the tampung tawar ritual. The practice may also create financial pressure when gift expectations exceed a family's means, although its form is negotiable. Doctrinal analysis finds no provision that makes Tutup Uban a statutory condition of marriage validity or registration. The study therefore interprets the tradition as a socially authoritative yet context-specific customary norm operating alongside, rather than replacing, religious and state-law requirements. Its contribution lies in clarifying the distinction between social legitimacy and formal legality within Indonesian legal pluralism. Practically, its symbolic purpose can be preserved through flexible implementation that avoids excessive financial demands.]]>
