# OS Open Names Technical Specification

OS Open Names is a geographic directory that contains basic information about identifiable places (i.e. named places). The content of the product is divided into themes based on type and local type classification values. The data contains accurate and current settlement names, road names and numbers, postcodes and their locations, with additional contextual information and links to other datasets. It is designed for use across all market sectors and can be used for web service and mobile development.

The primary use of the product is to provide the location for a named place to support a wealth of activities such as discovery, identification, visualisation, geocoding, routing and navigation, and linking diverse information.

## Product update schedule <a href="#id-1.1-product-update-schedule" id="id-1.1-product-update-schedule"></a>

OS Open Names is updated quarterly and released in April, July, October and January.

## Available formats <a href="#id-1.2-available-formats" id="id-1.2-available-formats"></a>

OS Open Names is available in the following formats:

* Comma-separated values (CSV)
* Geography Markup Language (GML) 3.1.2
* GeoPackage

## Coordinate reference system <a href="#id-1.4-coordinate-reference-system" id="id-1.4-coordinate-reference-system"></a>

The dataset uses the British National Grid spatial reference system. The National Grid coordinates are to a resolution of 0.1 metre. This is the resolution of the source data. Positions are described as Easting and Northing coordinates in units of metres.

## Index

* [Source of OS Open Names](https://docs.os.uk/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/os-open-names/os-open-names-technical-specification/source-of-os-open-names)
* [Viewing resolution](https://docs.os.uk/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/os-open-names/os-open-names-technical-specification/viewing-resolution)
* [Product structure](https://docs.os.uk/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/os-open-names/os-open-names-technical-specification/product-structure)
* [Feature type](https://docs.os.uk/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/os-open-names/os-open-names-technical-specification/feature-type)
* [Code lists](https://docs.os.uk/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/os-open-names/os-open-names-technical-specification/code-lists)
* [Structured data types](https://docs.os.uk/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/os-open-names/os-open-names-technical-specification/structured-data-types)
* [Local Type](https://docs.os.uk/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/os-open-names/os-open-names-technical-specification/local-type)
* [Supply formats overview](https://docs.os.uk/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/os-open-names/os-open-names-technical-specification/supply-formats-overview)
* [Attribute naming format comparison](https://docs.os.uk/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/os-open-names/os-open-names-technical-specification/attribute-naming-format-comparison)