Administrative Writing Before Decipherment: The ORCA Threshold and ARCH Protocol Applied to Proto-Cuneiform, Proto-Elamite, Rongorongo, and the Indus Valley Script

Companion to OSF project X2na5 (JPAR-RA-05261, under review). Introduces the ORCA threshold hypothesis (Oral-capacity, Resource-buffer, Contested-Allocation) and the ARCH protocol (Administrative Record Classification Heuristic), a six-step computational methodology for identifying administrative writing in any undeciphered corpus without phonetic decipherment. Applied to proto-cuneiform (6,691 tablets), rongorongo (146 tablet faces), and the Indus Valley script (2,511 seals). Five of six structural features replicate directionally across all three corpora spanning 3,700 years. Targeted for submission to Cambridge Archaeological Journal.