# AddressBase Fundamentals

The following AddressBase Fundamentals pages provide an overview of the 'family' of AddressBase products. They cover key elements of design for AddressBase products, including data formats, classification scheme, product supply, coordinate reference systems, currency, precision, and data sources, amongst other topics.

* [Release notes](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/release-notes)
* [AddressBase product family](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/addressbase-product-family)
* [Future and past publication dates](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/future-and-past-publication-dates)
* [Unique Property Reference Number (UPRN)](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/unique-property-reference-number-uprn)
* [Coordinate reference systems](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/coordinate-reference-systems)
* [Classification scheme](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/classification-scheme)
* [Data sources](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/data-sources)
* [Street names and numbering](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/street-names-and-numbering)
* [Currency, completeness and precision](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/currency-completeness-and-precision)
* [Product supply](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/product-supply)
* [Code lists and enumerations](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/code-lists-and-enumerations)
* [AddressBase local custodian codes](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/addressbase-local-custodian-codes)
* [AddressBase Islands local custodian codes](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/addressbase-islands-local-custodian-codes)

These pages should be used in conjunction with the detailed technical specifications for each product (which can be found under the top-level product page for each individual product from the left-hand-side menu).