> 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/water-portfolio/os-open-rivers/os-open-rivers-technical-specification/code-lists/hydronodecategoryvalue.md).

# HydroNodeCategoryValue

The [HydroNode](/os-downloads/products/water-portfolio/os-open-rivers/os-open-rivers-technical-specification/feature-types/hydronode.md) feature is attributed with a *hydroNodeCategory* with a data type of *hydroNodeCategoryValue*. The following table lists the codes which are used to populate this field and gives a description for each code.

{% hint style="info" %}
The code list has been inherited from INSPIRE and is not extendable.
{% endhint %}

## **Code list: HydroNodeCategoryValue**

Classification value defining the type of hydrographic node <http://inspire.ec.europa.eu/codelist/HydroNodeCategoryValue/>

| Code     | Description                                                                                                                                                         |
| -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| junction | A split in the network to indicate where three or more watercourses meet at the same level, for example, confluences or bifurcations.                               |
| outlet   | The end terminal of a set of one or more interconnected links that does not have any downstream flow, for example, sinks or the point where a river enters the sea. |
| source   | The start terminal of a set of one or more interconnected links that has downstream flow, for example, springs or collects.                                         |

Where the hydroNodeCategory has not been identified, this attribute is set to null and a *nilReason* of *inapplicable* is given. This will indicate where an attribute of the watercourse changes which requires a watercourseLink to split, for example, watercourseName. In the Esri shapefile, these are given the attribute value of *pseudo*.


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