# Data structure

The data structure of OS Open Greenspace in Geography Markup Language (GML) format is described by a Unified Modelling Language (UML) class diagram and accompanying tables containing text.

## Precision <a href="#bookmark2" id="bookmark2"></a>

OS Open Greenspace geometry is published with a precision of two decimal places.

## Classification scheme <a href="#bookmark3" id="bookmark3"></a>

OS Open Greenspace consists of the following classifications:

* Public parks or gardens
* Play spaces
* Golf courses
* Sports areas or playing fields
* Churchyards or burial grounds
* Allotments or community growing spaces

A full table of these classifications and associated Ordnance Survey real-world terms and their definitions is included in the [Function Value Code List](/os-downloads/products/land-and-terrain-portfolio/os-open-greenspace/os-open-greenspace-technical-specification/code-lists/functionvalue.md).

## Model overview <a href="#bookmark4" id="bookmark4"></a>

<figure><img src="/files/KbJw7sxadUdCjxoT1sSK" alt="Figure 2: UML class diagram for the Greenspace Site and Access Point Feature Types, and the Function Value and Access Type Value Code Lists"><figcaption><p>UML class diagram for the Greenspace Site and Access Point Feature Types, and the Function Value and Access Type Value Code Lists.</p></figcaption></figure>


---

# 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://docs.os.uk/os-downloads/products/land-and-terrain-portfolio/os-open-greenspace/os-open-greenspace-technical-specification/data-structure.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.