> 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/products/addresses-and-names-portfolio/addressbase-fundamentals/code-lists-and-enumerations/rpccode.md). # RPCCode This enumeration is used in association with the rpc/RPC attribute. This enumeration identifies the accuracy value of the coordinates allocated to the address.
ValueDescriptionImplementation notes
1Central Internal Position

The address seed is contained within an OS MasterMap Topography Layer building and within 2.5m of its calculated centre.

Or

The seed is in the best possible position based on the nature of the premises, for example, Development Land, House Boat, Wind Farm.

2General Internal Position

The address seed is contained within an OS MasterMap Topography Layer building but is more than 2.5m away from its calculated centre.

Or

The seed is in an internal position based on the nature of the premises, for example, Development Land, House Boat.

3Transitional Position

The address seed has been changed from provisional to live in the last six months. It has been captured to a high level of positional accuracy, but the OS MasterMap Topography Layer feature is not yet captured.

Please note the address seed will only be moved pending any imminent mapping updates.

4Street Location

The address seed is plotted in accordance with the declared street start or end coordinates.

Please note this is the highest accuracy possible for Street Records.

5Postcode Unit PositionThe address seed has been captured to Postcode Unit level. It will be updated when more information becomes available.
9Low accuracy – marked for priority reviewThis address seed has been captured to a lower level of accuracy and will be updated as a priority over the coming releases.
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