# Licence and attribution for Orca's data

Orca's corpus is published under the **Creative Commons Attribution 4.0 International licence
(CC BY 4.0)**, SPDX identifier `CC-BY-4.0`, full text at
<https://creativecommons.org/licenses/by/4.0/legalcode>.

This covers everything Orca writes: the records under `corpus/`, and everything the build
publishes from them, which today is `corpus.json`, `core.json`, `conflicts.json`, the per-rail and
per-record JSON files under `data/`, `llms.txt`, and the rendered pages.

## What you may do

Copy it, keep it, change it, build on it, and use it commercially. No fee, no registration, no
permission needed. CC BY 4.0 licenses the sui generis database right as well as copyright, so
extracting and reusing substantial parts of the corpus is covered too.

## What you must do

Give credit. A link is enough:

> Data from [Orca](https://qstve.com/orca/), CC BY 4.0. Snapshot YYYY-MM-DD.

Name the snapshot date you used, because payment rules change and a record is only as good as the
date on it. Every published JSON file carries a ready-made `license.attribution` string with its
own snapshot date in it. If you changed the data, say so, and do not imply Orca stands behind your
version.

## What this is not

Orca is reference material about published payment rules. **It is not legal, compliance or
financial advice**, it does not move money, and nothing in it authorises a payment, a return, a
reversal or a compliance determination. Every record carries a trust tier and a confidence; a
`draft` record has been written by an agent and checked by nobody. Read the tier and the
governing authority's own current text before you act on anything that matters. Orca is provided
as is, without warranties, to the extent the licence allows.

## What the licence does not cover

Orca cites rulebooks by section and edition. It does not reproduce their text, and it never will:
the rulebooks of Nacha, EPC, The Clearing House, the Federal Reserve, BCB, ISO and the rest stay
the copyright of their authors, under their own terms. CC BY 4.0 applies to Orca's own writing
about those documents, not to the documents. Following a citation into a source is your
responsibility under that source's terms.

Rail names, scheme names and trade marks belong to their owners. Orca uses them to say which rail
a rule belongs to. Nothing here is a claim to them, and no operator endorses Orca.

## Why this licence

CC BY 4.0 was chosen because it is the plainest widely understood open data licence that keeps
attribution: it is short, it is recognised by data publishers and by the tools that read licence
metadata, and version 4.0 handles database rights explicitly, which matters for a corpus. CC0
would drop the attribution Orca wants. ODbL would force share-alike on anyone who builds on the
data, which cuts against Orca being usable inside other people's systems. Changing this licence is
Dave's decision.