> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-plus-islands/addressbase-plus-islands-technical-specification.md).

# AddressBase Plus Islands Technical Specification

This technical specification provides detailed technical information about AddressBase Plus Islands. It is targeted at technical users and software developers.

{% hint style="info" %}
This product was designed to allow current customers of AddressBase Plus to add this product (AddressBase Plus Islands) to their current data holdings. This means there are columns in the schema of this product which will never be populated. These are identified on the appropriate pages throughout this specification document.
{% endhint %}

This technical specification includes the following sections:

* [Data formats](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-plus-islands/addressbase-plus-islands-technical-specification/data-formats.md)
* [Supply and update](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-plus-islands/addressbase-plus-islands-technical-specification/supply-and-update.md)
* [AddressBase Plus Islands structure](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-premium-islands/addressbase-premium-islands-technical-specification/addressbase-premium-islands-structure.md)
* [Feature types](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-plus-islands/addressbase-plus-islands-technical-specification/feature-types.md)
* [Code lists and enumerations](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-plus-islands/addressbase-plus-islands-technical-specification/code-lists-and-enumeration.md)
* [CSV to GML mapping](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-plus-islands/addressbase-plus-islands-technical-specification/csv-to-gml-mapping.md)
* [Example records](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-plus-islands/addressbase-plus-islands-technical-specification/example-records.md)

{% hint style="info" %}
All AddressBase products include the [Unique Property Reference Number (UPRN)](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-core-principles/unique-property-reference-number-uprn.md) and are based on same [coordinate reference systems](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-core-principles/coordinate-reference-systems.md). 

Please see the [General AddressBase information](/os-downloads/~/changes/AJZwzCsyrD9hiTbOxIbO/addressing-and-location/addressbase-core-principles.md) section for additional information that applies across all AddressBase products.
{% endhint %}


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