"EA-CORPORA-12 — The Twelfth Seating" is the gathering record of the twelfth corpus-seating run of the Crimson Hexagonal Archive's primary-source library (Lee Sharks, 6 September 2026). Two corpora are seated whole from a pinned commit of the Perseus canonical-greekLit repository: Diogenes Laertius, Vitae philosophorum (4,835 lines), and Strabo, Geographica (3,559 lines), bringing the library to sixty-one seats. The run was occasioned by the SE 34 and Second Letter work of the same days, which needed the transmission texts of the Aristotelian and Theophrastan books on the shelf: the four Peripatetic wills preserved in Diogenes Book V (Aristotle, Theophrastus, Strato, Lycon), the two catalogues with their stichometric totals (445,270 and 232,808 lines), the renaming of Tyrtamus at V.38, and Strabo XIII.1.54, where the custody of the books is narrated with παρέδωκεν three times — Aristotle to Theophrastus, Theophrastus to Neleus, Neleus to his heirs at Scepsis — through the trench, Apellicon's faulty restorations, Sulla and Tyrannion. These loci are recorded on the seats as verified loci. The deposit states the standing rule of the library: seatings go to data/corpora on alexanarch, render on the originals shelf of Training Layer Literature, and are periodically gathered into an EA-CORPORA deposit that links them — seat, shelf, and deposit being the bytes, the reading room, and the citable act. It names the pending seatings for the thirteenth run (Plutarch's Lives, Athenaeus, Aelian, the Delphic decree for Aristotle and Callisthenes, and the scan-class witnesses of the Elenchi: the Byzantine paraphrast, Michael of Ephesus, Albert the Great, Giles of Rome) and carries as an appendix the cut of the four wills. Two working notes produced from these seats are deposited separately: Catalogues and Wills, and The Stone for a List.