# Classification scheme The AddressBase Classification Scheme provides varying levels of classification for addresses which are captured and maintained by the Local Authorities and Ordnance Survey. This allows searches to be limited on residential or commercial addresses or be more specific to find all the flats or all fast-food outlets. The varying levels of classification are as follows: * Primary Level Classification\ R: Residential \ C: Commercial * Secondary Level Classification\ RD: Residential Dwelling\ CH: Hotel/Motel/ Boarding/ Guest House * Tertiary Level Classification \ RD02: Detached House\ CH01: Boarding/Guest House/ Bed And Breakfast/Youth Hostel * Quaternary Level\ CH01YH: Youth Hostel {% hint style="info" %} * The AddressBase Classification Scheme is applicable to all of the AddressBase products * The level of classification varies across all addressable objects and across the different AddressBase products. AddressBase provides primary level classification for addressable objects, AddressBase Core provides up to secondary level, while AddressBase Plus, AddressBase Plus Islands, AddressBase Premium and AddressBase Premium Islands provide up to tertiary / quaternary level. * There are only certain classification codes that extend to the quaternary classification level as shown above. {% endhint %} ## Use of third party data in classifications The AddressBase Classification Scheme incorporates selected third-party data sources to provide additional intelligence and contribute towards classification validation. ## AddressBase Classification Scheme download The full AddressBase Classification Scheme is available in CSV (comma-separated values) and .xlsx formats for download in the following zip file: {% file src="" %} {% hint style="info" %} The AddressBase product classification scheme was last updated on **17 January 2025** {% endhint %} --- # 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/addresses-and-names-portfolio/addressbase-fundamentals/classification-scheme.md?ask= ``` 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.