> 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-core-principles/classification-scheme.md).

# Classification scheme

The AddressBase Classification Scheme provides varying levels of classification for addressable objects 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 level of classification varies across all addressable objects and across the different products. 
{% endhint %}

There are only certain classification codes that extend to the quaternary classification level as shown above. A full list of the classification codes can be found on our [Product Support](https://www.ordnancesurvey.co.uk/business-government/tools-support/addressbase-premium-support) page on the OS website.

## Classification Scheme download

The full classification scheme is available in CSV and .xlsx formats for download in the following zip file.

{% file src="/files/R5DoSevYs3YtfN0BpOKe" %}


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