# Policy corpus

> Two versions of a data retention policy, each with a validity window, the second superseding the first: version control for regulated knowledge.

Source: https://openmoca.org/examples/policy-corpus/

**Download** both versions, [`policy-corpus-retention-2025.moca`](https://github.com/openmoca/moca-spec/releases/latest/download/policy-corpus-retention-2025.moca) and
[`policy-corpus-retention-2026.moca`](https://github.com/openmoca/moca-spec/releases/latest/download/policy-corpus-retention-2026.moca), from the [latest release](https://github.com/openmoca/moca-spec/releases/latest).

Two versions of one policy package, `data-retention@1.0.0` and `@2.0.0`. Each
states when it is in force (`validFrom`, `validUntil`), and 2.0.0 declares that
it `supersedes` 1.0.0. 2.0.0 is signed with the examples publisher key.

When a Reader has both loaded, with a trust root whose publisher key covers the
policy's id (the examples trust root, `example-trust-root.json`, lets it speak
for `https://example.com/`), the 1.0.0 nodes carry `superseded: true` in their
citation records, and the default retrieval policy leaves them out. Without a
trust root the relation is reported (`R004`) and has no effect
([package spec §7.2](/spec/package/#72-relations)). Both
versions stay readable and auditable, so "what did the policy say in 2025?"
still has an answer.

## Try it

[Try OpenMOCA](https://try.openmoca.org/p/data-protection-act) has the Data Protection Act 2018, section by section: the same idea, with only what is in force returned.

To try them with your AI assistant, use our [MCP server](/tools/mcp/). Download [`policy-corpus-retention-2025.moca`](https://github.com/openmoca/moca-spec/releases/latest/download/policy-corpus-retention-2025.moca) and [`policy-corpus-retention-2026.moca`](https://github.com/openmoca/moca-spec/releases/latest/download/policy-corpus-retention-2026.moca) into one folder, and serve the folder:

```sh
moca-mcp --library .
```

One download with nothing to install, for Windows, macOS or Linux: [get moca-mcp](/tools/mcp/#install).

Connect it to Claude Desktop, Claude Code, VS Code or Cursor, with full paths, as in [Got a .moca file?](/start/open-a-package/#connect-it). Then ask: "How long are customer records kept? Which version of the policy says so?"