about
About Plenum
A small site about old factory documents, meant to read well on a phone in a garage.
who built this
Plenum is by Phil Renato, built through Iterative LLM Co-Authorship — a working method described at renato.design where it lives alongside a small suite of design instruments. Plenum reads broadcast sheets, fender tags, and SPID labels. It exists because I own some of these cars and got tired of decoder pages that confused certainty for thoroughness.
what it is, what it isn't
- It is a deterministic decoder for factory production documents — Chrysler broadcast sheets and fender tags 1968–1974, GM SPID labels and door plates 1982–1992 — with every code citation-tagged and every uncertainty marked.
- It is not a registry, a price guide, an authentication service, or a forum.
- It is not generative at the decode. The decode engine is pure-TypeScript and deterministic — no AI in the hot path, no fabricated VINs, no AI-drawn cars or documents. The silhouettes use a generative model only as a ghost step that gets traced into a single closed shape and discarded. The vocabularies, citations, and encyclopedia were drafted with Claude under Phil’s direction (ILCA — Iterative Loop of Claude & Author), then cross-checked against the cited sources.
rights
Plenum is © Phil Renato 2026, all rights reserved. Plenum is published as a working website at renato.design/plenum-app. The source code, encyclopedia entries, concordance essays, and code-vocabulary compilations are not licensed for redistribution. Quotation under fair use is welcome with attribution back to Plenum and the underlying source.
The codes themselves — V, FE5, Y84, WM23, LB9 — are facts and not copyrightable; you can use them anywhere. The compilation, the citation discipline, the honest-uncertainty layer, and the writing on top are the work product. Wikipedia content cited by Plenum carries CC BY-SA 4.0 upstream; US government work product is public domain; factory shop manuals and printed reference works are cited (not reproduced) under fair use for facts. See concordance · mechanism for the full posture.
accuracy proviso — the Ship of Theseus problem
Plenum decodes the documents. It does not authenticate the parts on the car today. Those are different questions, and the gap between them is the oldest one in the field — Theseus's ship, restored a plank at a time over a long enough interval that no original wood remains, was the same paradox the Athenians argued over, and it's the same paradox a 1970 Hemi 'Cuda raises when its engine has been freshened, its quarters replaced, its tag remade, its trim retrimmed. Is it the same car? The factory documents tell you what came down the line in 1970. They do not tell you what is bolted to the unibody now. Plenum reads the first question; the registries and the marque experts adjudicate the second.
When a code is registered as factory-documented, that means: this is what the factory documents say the car was built with, corroborated against multiple cited sources. When a code is registered as registry-corroborated or registry-attested, registry data extends the read. When it's forum-consensus or single-source, lean lighter on it. When it's disputed, Plenum shows both readings.
Mistakes happen. A corrections channel is on the roadmap; until then Plenum reads what the documents say and surfaces the disputed cases in front of you so you can adjudicate from the cited sources.
Plenum is part of renato.design. Companion projects include design instruments for type, gesture, photogrammetry, and Grasshopper. None of them is paid; none of them mines you.