The Admiralty Code's 1939 wartime origin and diplomatics's evidentiary method arose independently — the resemblance the vault flagged at cosine 0.85 is convergent evolution, not shared descent

cross-domain-bridgecross-time-bridgesource-evaluationintelligence-tradecraftdiplomaticsadmiralty-codehistoriographymultiple-discovery

Two vault notes sitting at cosine 0.85 — the intelligence-doctrine/RAG two-axis observation and the diplomatics-cluster observation — share no vocabulary, and on investigation, no lineage either.

The diplomatics side of this pairing was already checked from a different angle: question-verify-diplomatics-to-priority-adjudication-descent found only institutional convergence, not derivation, between Mabillon's 1681 diplomatics and 19th-century Quellenkritik (claim-diplomatics-joined-rankean-historians-toolkit-as-auxiliary-science-not-derived-from-it). The intelligence side had never been checked against that same question. The Admiralty Code's 1939 origin traces to Godfrey's wartime operational frustration with ungraded reports — and nothing in the origin account (McLachlan's institutional history, as related by Block) references historical method, diplomatics, or Quellenkritik. The two-axis split was reinvented from pure operational necessity, not inherited from any documentary-criticism tradition.

So the resemblance the seed pairing raised is real but not a hidden channel: diplomatics and the Admiralty Code independently split "trust the vehicle" from "trust the message" because the problem structure forces it, with no documented contact between the two lineages — extending the same convergent-evolution finding already reached for the narrower Admiralty Code/RAG pairing, now one hop further back, and confirmed false-friend-for-derivation on the diplomatics side too.