# RAG freshness: choose the policy that applies

Store effective dates and supersession information with policy sources. Decide which version applies to the question, including whether the user is asking about today or a historical date. Retrieval similarity alone is not a policy-version rule.

## Worked example

Two synthetic policies have identical headings. Revision A applies through September; revision B applies from October. A question about an October event should use B, while a historical September question may correctly require A.

## Copyable prompt

```text
Build a source-selection test for [POLICY ASSISTANT]. Inputs include document ID, version, effective_from, effective_to, supersedes and user access. Include a current question, a historical question, overlapping dates and an undated source. State which source applies and when the assistant must ask or abstain. Do not treat retrieval score as proof of applicability.
```

## Checklist

- Store effective dates and supersession relationships.
- Distinguish current from historical questions.
- Test overlapping or missing dates.
- Return the applicable source and its version.

## Further reading

[Anthropic: citations and source references](https://platform.claude.com/docs/en/build-with-claude/citations)