Suep cata (สืบชะตา — "to prolong the fate") is the great life-extension ceremony of the north: the rite that lengthens a threatened lifespan, renews waning fortune and wards off a fate the horoscope has read as failing. It is one of the most characteristic and still most widely performed of Lanna rituals, and the catalogue holds 21 witnesses whose titles name it. Small in count, it is outsized in importance — 20 of the 21 are flagged research-priority (95%), the densest priority-share of any subject the scorer touches.
Suep cata is the hinge at which reading fate turns into changing it. The titles put the two operations side by side — "Suep anyu, Poet cata": open the horoscope (poet cata), then extend the life (suep anyu). The astrologer's holasat diagnoses the crisis; the suep cata rite is the intervention. This is the clearest single answer in the collection to what the saiyasat is for: not merely to know the future but to act on it, to buy back time against a bad reckoning.
And it works at every scale. The manuscripts prescribe suep cata for a single person, for a monk alone (Pap suep cata phikkhu ton diao), for the rice (Suep cata khao), and — strikingly — for the whole town: Suep cata ban mueang, the collective life-extension of the muang itself. The same ritual logic that renews one body renews the body politic.
It is a working ritual manual on paper — 17 mulberry-paper against 4 palm-leaf — barely dated (3 witnesses, 1902–1939) and late, exactly the profile of a text in active use rather than archival storage. It clusters in Nan (10) and Phayao (6), scattered across small vernacular temples with no dominant library — the wichaa survival pattern, the opposite of the canon's Wat Sung Men gravity.