Werbos, on the record — DARPA kept his backpropagation report out of DOCSUB, and the 1978 journal version shipped without the how-to appendix

Per Werbos's participant-approved oral history (p. 351, read directly at capture level): he used backpropagation to re-estimate a DARPA-funded, classified Joint Chiefs conflict-forecasting model and found it "had almost no predictive power." Then, in his words: "DARPA wasn't happy when I published that result… Therefore, the report, which included backpropagation in detail and other advanced methods, was not even entered into DOCSUB. Every time I tried to enter it into DOCSUB, somebody jiggled influence… 'This is too hot.'" The journal version appeared anyway — "they couldn't block the journals" — as the 1978 IEEE SMC paper on "dynamic feedback" which "calculates derivatives in a single swoop."

The nuance a careless retelling collapses (preserved from the capture's own catch): Werbos names two parallel reasons for the missing appendix. The fuller technical report was institutionally blocked from DOCSUB; the journal article separately lacked the appendix "because of page limits for a journal article." Blocked report and page-limited article are two documents with two reasons — the popular one-clause version ("DARPA suppressed the backprop appendix") over-fuses them.

Weight-bearing capacity: this is Tier 1 for Werbos said this, on the record — and single-witness for the institutional mechanism itself (no DARPA-side memo, second participant, or contemporaneous account located; possibly none public). Bibliographic identity of the paper (Werbos & Titus, SMC-8(9):657–666) carries [unverified-quant].

Pattern siblings: claim-werbos-tsp-manual-first-publication (the manual before it), claim-linnainmaa-priority-not-paternity and claim-parker-1985-technical-report-not-cited (other channels by which the algorithm kept missing its audience), backpropagation-gap.

Sibling gap, same witness: claim-werbos-1968-cybernetica-earliest-germ records the earlier Werbos "missing document" — the lost 1968 Cybernetica scan. Both notes' narrative core comes from the same June 1993 oral-history sitting quoted above (Talking Nets ch. 15, pp. 335–353), sixteen pages apart in one transcript, not two independently corroborated episodes (2026-08-01-hop-werbos-shared-witness).