# Code lists and enumerations

A code list is a controlled set of values for a free text data type which can be extended. This section identifies the code lists used within OS Open Roads and describes their values.

* [RoadClassificationValue](https://docs.os.uk/os-downloads/products/transport-network-portfolio/os-open-roads/os-open-roads-technical-specification/code-lists-and-enumerations/roadclassificationvalue)
* [RoadFunctionValue](https://docs.os.uk/os-downloads/products/transport-network-portfolio/os-open-roads/os-open-roads-technical-specification/code-lists-and-enumerations/roadfunctionvalue)
* [FormOfWayValue](https://docs.os.uk/os-downloads/products/transport-network-portfolio/os-open-roads/os-open-roads-technical-specification/code-lists-and-enumerations/formofwayvalue)
* [RoadStructureValue](https://docs.os.uk/os-downloads/products/transport-network-portfolio/os-open-roads/os-open-roads-technical-specification/code-lists-and-enumerations/roadstructurevalue)
* [FormOfRoadNodeValue](https://docs.os.uk/os-downloads/products/transport-network-portfolio/os-open-roads/os-open-roads-technical-specification/code-lists-and-enumerations/formofroadnodevalues)