“Implicit state silently shapes output. When any subsystem reads state the user did not just set, that state must be surfaced visibly at the point of action — or the system produces output the user cannot predict from the visible UI.”
Surfaced:Build 3114 (Sacred Accident codification — surfaced by the 19-build B3094-B3113 session that closed FOUR distinct instances of the same root pattern in one week). Unlike SA#19-SA#27 which were ratified at the close of per-genre WAR Rooms, SA#28 was surfaced by the operator-noticed pattern across CONTAMINATION BUGS rather than by a craft audit. It is closer in shape to SA#18 (cadence ritual meta-drift) than to the genre-craft SAs — both describe meta-patterns where the system's behavior diverges from what the visible surface implies. The four canonical examples: (1) Vault corpus contamination (B3104) — corpus had no arc filter; worship + Christian-hip-hop songs dominated SuperStyle embedding mean across every arc. (2) Customize panel in batch mode (B3104 investigation) — ForgeV2BatchPanel hardcoded cleanMode='' overriding visible Customize panel state. (3) Splice handoff degeneration (B3106) — use-forge-handoffs auto-enabled splice with the SAME genre on both sides when user deep-linked from /genres/[arc]. (4) Surprise Mode visual lie (B3105) — button rendered in active/selected style even when the user had not toggled it.
The anti-pattern this names
Every generic LLM-assisted codebase produces this pattern eventually: a subsystem reads state from a source the operator did not just touch (an inherited handoff, an ambient corpus filter, a hardcoded panel default, a visual style that implies selection), and the gap between "what the visible surface implies the system will do" and "what the system actually does" becomes a contamination class. The B3094-B3113 instances all followed the same forensic shape: operator saw output X, predicted output Y based on visible surface state, the gap was an implicit-state channel the surface did not expose. Single-layer fixes leave the class alive in adjacent code paths; the cure is multi-layer + structural — name the state in the comment, render it visibly in the surface, make the visible render reflect the ACTUAL value not the default.
The check
The four shipped fixes operationalize the rule: (a) B3104 Vault filter — explicit `arc_slug` filter on every Vault corpus query used by SuperStyle generation; contamination eliminated at the query layer. (b) B3105 Surprise-button visual — default render flipped to the dark/inactive style so visible state matches actual state. (c) B3106 Splice handoff — same-genre splice handoffs collapse to no-splice at three layers (handoff seeding, body-builder server-side, SuperStyle re-derivation) so the regression is visible the moment any future change re-opens any one of them. (d) B3114 Catalog source-arc badge — added per-card arc chips to PromptBatchPicker (/genres/[slug]/prompts) and GenreLibraryBatchPreview (forge batch mode); arc identity no longer inferred from URL context, every card carries its own source-arc identity. The triple-locking discipline from B3106-B3108 generalizes: when a contamination class is identified, fix it at every layer where the implicit channel exists. SA#28 is the most operational of the meta-SAs because every canonical example shipped a code-level fix. Relationship to SA#18: cadence-ritual drift IS implicit-state drift at the team-process layer — the cure for both is identical (surface the implicit state at the point of action). Canonical phrasing: `BRAND.sacredAccident28`.
Share this discipline
“Implicit state silently shapes output. When a subsystem reads state the user did not just set, that state must be surfaced visibly at the point of action — or the system produces output the user cannot predict from the visible UI. — Sacred Accident #28”
Why this gets its own permalink
Each Sacred Accident is a discipline this codebase operates under — a rule named on the public record, enforced in the build pipeline, and cited in every commit that advances the moat it protects. Permalinking each one turns the discipline into a teaching artifact: a buyer or partner who reads this page can cite the exact principle we operate under without grepping our docs.
Canonical phrasing: BRAND.sacredAccident28 · Doc: docs/SACRED-ACCIDENTS.md