# Technical specification

This technical specification explains the content of the OS Names API and the methods you can use to call it.

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This technical specification extends the Infrastructure for Spatial Information in the European Community (INSPIRE) Geographical Names theme to ensure compliance with European open data initiatives.
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If you are not familiar with the OS Names API, please read the [overview documentation](/os-apis/accessing-os-apis/os-names-api.md) before proceeding.
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## Core concepts

This specification does not cover core concepts that apply to all Ordnance Survey APIs.

Please read the following pages to learn more about OS API core concepts:

* [Authentication](/os-apis/core-concepts/authentication.md)
* [Error codes](/os-apis/core-concepts/error-codes.md)
* [Rate-limiting policy](/os-apis/core-concepts/rate-limiting-policy.md)

## API reference

The OS Names API is an API, which returns queries to the service in either XML or JSON. The service offers two resources:

<table data-view="cards"><thead><tr><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><strong>Find</strong></td><td>Return matched features based on a free text search.</td><td><a href="/pages/KBrVwSLdTaFk6DI0eD08">/pages/KBrVwSLdTaFk6DI0eD08</a></td></tr><tr><td><strong>Nearest</strong></td><td>Return the closest features to a pair of coordinates (X and Y).</td><td><a href="/pages/aO0k3ChV0iZwXeUD38Dw">/pages/aO0k3ChV0iZwXeUD38Dw</a></td></tr></tbody></table>


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