# Reference

Exact, complete look-up pages.

- [Recipe format](recipe-format.md): the frame, parameter shapes, bounds by engine, numbers, names and units.
- [Fields](fields.md): every field of every schema, with its unit.
- [Outputs](outputs.md): the result dict, the report files, the engines' own files and the failure record.
- [Messages](messages.md): validation errors, warning codes and failure reasons.
- [ID index](ids.md): every engine-behavior (EB) and known-issue (KI) ID, with a link to its entry.
- [Known issues](known-issues.md): PowderLine's own known, deliberately deferred behaviors, by `KI-NN` ID.
- [Command line](cli.md): the `powderline` command and every option.
- [Python API](api.md): `powderline.run`, `validate` and the public names.
- [Versions and compatibility](versions.md): what a version promises, the support matrix and the schema history.
- [Scope and limitations](scope.md): what PowderLine does not do.
- [Glossary](glossary.md): the terms these pages use.

```{toctree}
:maxdepth: 1
:hidden:

recipe-format
fields
outputs
messages
ids
known-issues
cli
api
versions
scope
glossary
```