Claude Code First, specification version 0.1.0. The plain-language guide
Version 0.1.0. Level 1. Best evidence grade R2/S3.
PG-4 What outlives the task leaves its rationale first
Where shipping deletes a rationale section, what in it outlives the task MUST first be moved into the code it explains, the ledger entry or a decision record.
| Field | Value |
|---|---|
| Keyword | MUST |
| Level | 1 |
| Checked | by judgement |
| Findings | F106 |
| Harness facts | none |
| Threat | internal: both losses are one tool's behaviour, recorded by the researcher's own tool |
| Status | active |
Rationale: shipping deleted a task's rationale, and twice what only the rationale held was lost with it: that a design had been wrong, and a block's definition of done, counted at 131 entries and six reopenings (F106, R2/S3). A measured incident admits MUST. The rule is conditional because the loss is caused by deletion at shipping, which is roadkeep's design and not something the evidence recommends: deleting keeps the file small, and the cost of the alternative was never observed. A tool that does not delete rationale meets the rule trivially. The reasons are not destroyed, since history keeps them, but no later session reads history before deciding.