# Controlled Vocabularies

OpenActive uses a number of [Controlled Vocabularies](https://en.wikipedia.org/wiki/Controlled_vocabulary) (including the [Activity List](/guide-to-openactive-on-github/activity-list.md)) in order to ensure the consistency and quality of OpenActive data. These are all expressed in SKOS, and developers working on Controlled Vocabularies may thus also wish to review [OpenActive's `skos` repos](/guide-to-openactive-on-github/skos.md).

* [**activity-list**](https://github.com/openactive/activity-list)**:** The code used to parse Activity List data and present it via the web front-end.
* [**accessibility-support**](https://github.com/openactive/accessibility-support)**:** A small JSON-LD vocabulary describing different classes of impairment.
* [**facility-types**](https://github.com/openactive/facility-types)**:** A JSON-LD vocabulary describing leisure centre and sport facilities.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://developer.openactive.io/guide-to-openactive-on-github/controlled-vocabularies.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.