# Evidence Hygiene

> Curate the evidence needed to reproduce a result and exclude everything retention rules forbid — credentials, raw logs, bulk output.

**Tier:** 0 · **Normative weight:** implements `TM-EVD-008`
**Requires:** nothing

## Problem it removes

Evidence capture defaults to "keep everything": raw logs, full model
output, whole databases, screenshots with secrets in frame. The record
becomes unreviewable, retention boundaries are violated by accident, and
the one command that would reproduce the result is buried in noise.

## Mechanism

Two written lists, kept where evidence is captured — the declared retention
boundary `TM-EVD-008` requires. **Curate:** the
commands run, digests, timings, and metadata needed to reproduce or verify
the result. **Never add:** credentials, customer data, raw logs or traces,
model prompts and output, databases, weights, binaries, copies of runtime
checkouts — plus whatever the repository's own privacy, legal, and
ownership boundaries forbid. A recovery-safe reference or curated
observation is often more truthful than an uncontrolled duplicate; the
record states what it proves and what deliberately remains outside the
system.

## Cost

Authoring: minutes — the lists are short. Per change: a moment of judgment
at each capture, which is judgment the capture needed anyway. Per session:
none.

## Do not adopt when

Never skip the exclusion list in a repository that captures evidence at
all. The pattern only lacks a subject where no evidence is recorded.

## Evidence

Assessed in [inference-ops](/docs/truth-machine/implementations/inference-ops/)
and [cloud-ops](/docs/truth-machine/implementations/cloud-ops/), where the
lists live in the scoped guidance of the directories that capture evidence.

## Template

None — adopted by convention, as a section of the front door or the
evidence directory's scoped guidance.

## Related patterns

[Evidence Packet](/docs/truth-machine/kit/evidence-packet/) gives curated
evidence a durable identity.
[Untrusted Intake](/docs/truth-machine/kit/untrusted-intake/) governs what
arrives before curation.