# PDD-04 — Avoid Sunk Cost Fallacy
Token: PDD-04
Version: v1

## Rule

Keep work because it has current value, not because someone already spent time on it.

Delete work that has no current use and no committed plan. When a real need returns, rebuild from current requirements.

Git history is sufficient recovery for deleted work. The active tree must describe the current system.

### Exceptions

Keep work that has a named owner, a committed delivery plan, and a near review date.

Until the repository reaches a recorded removal condition, keep required compatibility code.

## Rationale

Agents treat preserved drafts and unused code as approved directions. Preserved work can acquire false authority even when it has no current value.

## History

- v1 (2026-08-24): Published to prevent unused work from becoming false authority for later changes.