> 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/land-and-terrain-portfolio/os-terrain-5/os-terrain-5-technical-specification/gml-feature-types.md).

# GML Feature types

The feature types within the contours enable their representation as individual features to allow for easier interpretation; for example, the contours can be drawn as different colours to highlight the index contours, the high-water mark, and spot heights over a certain value. The contours and tidelines have been rounded to two decimal places.

The column names have been reformatted to facilitate compliance with Esri software.

## **Contour line feature type**

| Column name      | Type           | Description                  |
| ---------------- | -------------- | ---------------------------- |
| +geometry        | GM\_LineString | The structure of the feature |
| +propertyValue   | Distance       | The length of the contour    |
| +contourLineType | String         | master ordinary auxiliary    |

{% hint style="info" %}
*The ContourLine sub-type value names align with INSPIRE draft elevation specification. The terms 'master' and 'ordinary' represent the more traditionally recognised terms index and standard (contours) respectively.*
{% endhint %}

## **SpotHeight feature type**

| Column name     | Type      | Description                                                                      |
| --------------- | --------- | -------------------------------------------------------------------------------- |
| +geometry       | GM\_Point | The structure of the feature.                                                    |
| +propertyValue  | Distance  | The z value (height above Newlyn, or other British height datum) of the feature. |
| +spotHeightType | String    | <p>formSpot generic mountainPass</p><p>summit</p>                                |

{% hint style="info" %}
*At launch only the sub-type value 'generic' has been used but the other values provide functionality to enrich the attribution if required in a later product release.*
{% endhint %}

## **LandWaterBoundary feature type**

| Column name    | Type           | Description                      |
| -------------- | -------------- | -------------------------------- |
| +geometry      | GM\_LineString | The structure of the feature.    |
| +propertyValue | Distance       | The length of the boundary line. |

| Column name         | Type   | Description                                                                      |
| ------------------- | ------ | -------------------------------------------------------------------------------- |
| +waterLevelCategory | String | <p>meanHighWater meanLowWater meanHighWaterSprings</p><p>meanLowWaterSprings</p> |

{% hint style="info" %}
*At launch only the sub-type value 'generic' has been used but the other values provide functionality to enrich the attribution if required in a later product release.*
{% endhint %}

### **Example of the ContourLine feature type**

```xml
<os:member>
<os:ContourLine gml:id="os.t5.sx98se.175">
<os:geometry>
<gml:LineString srsName="urn:ogc:def:crs:EPSG::27700" gml:id="os.t5.sx98se.175.geom">
<gml:posList>295487.08 80000 295481.21 80001.48 295480.55 80001.23
295481.75 80000</gml:posList>
</gml:LineString>
</os:geometry>
<os:propertyValue uom="m">15</os:propertyValue>
<os:contourLineType>ordinary</os:contourLineType>
</os:ContourLine>
</os:member>
SpotHeight feature type
<os:member
<os:SpotHeight gml:id="os.t5.sx98se.0">
<os:geometry>
<gml:Point srsName="urn:ogc:def:crs:EPSG::27700" gml:id="os.t5.sx98se.0.geom">
<gml:pos>299161.48 84990.56</gml:pos>
</gml:Point>
</os:geometry>
<os:propertyValue uom="m">31.9</os:propertyValue>
<os:spotHeightType>generic</os:spotHeightType>
</os:SpotHeight>
</os:member>
Example of the LandWaterBoundary feature types
<os:member>
<os:LandWaterBoundary gml:id="os.t5.sx98se.17">
<os:geometry>
<gml:LineString srsName="urn:ogc:def:crs:EPSG::27700" gml:id="os.t5.sx98se.17.geom">
<gml:posList>297786.59 81469.64 297783.26 81469.75 297783.26
81466.75 297786.59 81469.64</gml:posList>
</gml:LineString>
</os:geometry>
<os:propertyValue uom="m">1.62</os:propertyValue>
<os:waterLevelCategory>meanHighWater</os:waterLevelCategory>
</os:LandWaterBoundary>
</os:member>
```


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