# ClassificationCode

This code list describes the classification code for each feature. The classification codes will be expanded as necessary for future releases.

<table><thead><tr><th width="128">Value</th><th width="454">Description</th></tr></thead><tbody><tr><td>CT18CA</td><td>Aqueduct Over Canal.</td></tr><tr><td>CT18MU</td><td>Aqueduct Over Multiple.</td></tr><tr><td>CT18NN</td><td>Aqueduct Over No Network.</td></tr><tr><td>CT18PA</td><td>Aqueduct Over Path.</td></tr><tr><td>CT18RA</td><td>Aqueduct Over Railway.</td></tr><tr><td>CT18RO</td><td>Aqueduct Over Road.</td></tr><tr><td>CT18WA</td><td>Aqueduct Over Water.</td></tr><tr><td>CT16CA</td><td>Bridge Over Canal.</td></tr><tr><td>CT16MU</td><td>Bridge Over Multiple.</td></tr><tr><td>CT16NN</td><td>Bridge Over No Network.</td></tr><tr><td>CT16PA</td><td>Bridge Over Path.</td></tr><tr><td>CT16RA</td><td>Bridge Over Railway.</td></tr><tr><td>CT16RO</td><td>Bridge Over Road.</td></tr><tr><td>CT16WA</td><td>Bridge Over Water.</td></tr><tr><td>CT19CA</td><td>Canal Aqueduct Over Canal.</td></tr><tr><td>CT19MU</td><td>Canal Aqueduct Over Multiple.</td></tr><tr><td>CT19NN</td><td>Canal Aqueduct Over No Network.</td></tr><tr><td>CT19PA</td><td>Canal Aqueduct Over Path.</td></tr><tr><td>CT19RA</td><td>Canal Aqueduct Over Railway.</td></tr><tr><td>CT19RO</td><td>Canal Aqueduct Over Road.</td></tr><tr><td>CT19WA</td><td>Canal Aqueduct Over Water.</td></tr><tr><td>CT22CT</td><td>Canal Tunnel.</td></tr><tr><td>CT22CP</td><td>Canal Tunnel Portal.</td></tr><tr><td>CT17CA</td><td>Footbridge Over Canal.</td></tr><tr><td>CT17MU</td><td>Footbridge Over Multiple.</td></tr><tr><td>CT17NN</td><td>Footbridge Over No Network.</td></tr><tr><td>CT17PA</td><td>Footbridge Over Path.</td></tr><tr><td>CT17RA</td><td>Footbridge Over Railway.</td></tr><tr><td>CT17RO</td><td>Footbridge Over Road.</td></tr><tr><td>CT17WA</td><td>Footbridge Over Water.</td></tr><tr><td>CT14MJ</td><td>Motorway Junction.</td></tr><tr><td>CT20CA</td><td>Multi-Network Bridge Over Canal.</td></tr><tr><td>CT20MU</td><td>Multi-Network Bridge Over Multiple.</td></tr><tr><td>CT20NN</td><td>Multi-Network Bridge Over No Network.</td></tr><tr><td>CT20PA</td><td>Multi-Network Bridge Over Path.</td></tr><tr><td>CT20RA</td><td>Multi-Network Bridge Over Railway.</td></tr><tr><td>CT20RO</td><td>Multi-Network Bridge Over Road.</td></tr><tr><td>CT20WA</td><td>Multi-Network Bridge Over Water.</td></tr><tr><td>LO02CR</td><td>Named Area Of Coastal Rock.</td></tr><tr><td>CT07RL</td><td>Named Area Of Railway Land.</td></tr><tr><td>LW04AS</td><td>Named Area Of Sea.</td></tr><tr><td>LW04BA</td><td>Named Bay.</td></tr><tr><td>LO02CH</td><td>Named Cirque Or Hollow.</td></tr><tr><td>LO02CS</td><td>Named Cliff Or Slope.</td></tr><tr><td>LO02HD</td><td>Named Coastal Headland.</td></tr><tr><td>LO02RA</td><td>Named Coastal Ravine.</td></tr><tr><td>LW04ES</td><td>Named Estuary.</td></tr><tr><td>LO02GI</td><td>Named Group Of Islands.</td></tr><tr><td>LW04HA</td><td>Named Harbour.</td></tr><tr><td>LO02HM</td><td>Named Hill Or Mountain.</td></tr><tr><td>LW04IM</td><td>Named Inland Water Marsh.</td></tr><tr><td>LO02IS</td><td>Named Island.</td></tr><tr><td>ZM05LS</td><td>Named Linear Structure.</td></tr><tr><td>LO02CL</td><td>Named Other Coastal Landform.</td></tr><tr><td>LO02GA</td><td>Named Other Geographic Area.</td></tr><tr><td>LO02OC</td><td>Named Other Land Cover.</td></tr><tr><td>LO02OL</td><td>Named Other Landform.</td></tr><tr><td>LO02RH</td><td>Named Range Of Hills Or Mountains.</td></tr><tr><td>LO02SH</td><td>Named Spot Height.</td></tr><tr><td>LW04IW</td><td>Named Stretch Of Inland Water.</td></tr><tr><td>LW04TW</td><td>Named Stretch Of Tidal Water.</td></tr><tr><td>LO02TC</td><td>Named Tidal Land Cover.</td></tr><tr><td>LO02NV</td><td>Named Valley.</td></tr><tr><td>LW04WF</td><td>Named Waterfall.</td></tr><tr><td>CT22PT</td><td>Pedestrian Tunnel Or Subway.</td></tr><tr><td>CT22PP</td><td>Pedestrian Tunnel Or Subway Portal.</td></tr><tr><td>CT22TT</td><td>Rail Tunnel.</td></tr><tr><td>CT22TP</td><td>Rail Tunnel Portal.</td></tr><tr><td>CT15CA</td><td>Railway Bridge Over Canal.</td></tr><tr><td>CT15MU</td><td>Railway Bridge Over Multiple.</td></tr><tr><td>CT15NN</td><td>Railway Bridge Over No Network.</td></tr><tr><td>CT15PA</td><td>Railway Bridge Over Path.</td></tr><tr><td>CT15RA</td><td>Railway Bridge Over Railway.</td></tr><tr><td>CT15RO</td><td>Railway Bridge Over Road.</td></tr><tr><td>CT15WA</td><td>Railway Bridge Over Water.</td></tr><tr><td>CT11CA</td><td>Road Bridge Over Canal.</td></tr><tr><td>CT11MU</td><td>Road Bridge Over Multiple.</td></tr><tr><td>CT11NN</td><td>Road Bridge Over No Network.</td></tr><tr><td>CT11PA</td><td>Road Bridge Over Path.</td></tr><tr><td>CT11RA</td><td>Road Bridge Over Railway.</td></tr><tr><td>CT11RO</td><td>Road Bridge Over Road.</td></tr><tr><td>CT11WA</td><td>Road Bridge Over Water.</td></tr><tr><td>CT14RJ</td><td>Road Junction.</td></tr><tr><td>CT22RT</td><td>Road Tunnel.</td></tr><tr><td>CT22RP</td><td>Road Tunnel Portal.</td></tr><tr><td>CT14RD</td><td>Roundabout.</td></tr><tr><td>🆕CT13SA</td><td>Slipway.</td></tr><tr><td>CT22MT</td><td>Tube Or Metro Tunnel.</td></tr><tr><td>CT22MP</td><td>Tube Or Metro Tunnel Portal.</td></tr><tr><td>CT21CA</td><td>Underpass Under Canal.</td></tr><tr><td>CT21MU</td><td>Underpass Under Multi-Network.</td></tr><tr><td>CT21NN</td><td>Underpass Under No Network.</td></tr><tr><td>CT21RA</td><td>Underpass Under Railway.</td></tr><tr><td>CT21RO</td><td>Underpass Under Road.</td></tr><tr><td>CT22WT</td><td>Watercourse Tunnel.</td></tr><tr><td>CT22WP</td><td>Watercourse Tunnel Portal.</td></tr><tr><td>🆕CT11WE</td><td>Weir.</td></tr></tbody></table>

{% hint style="info" %}
The OS Emergency Services Gazetteer Classification Scheme is available to download from the [OS ESG Downloads page](/os-downloads/products/addresses-and-names-portfolio/os-emergency-services-gazetteer/os-esg-downloads.md).
{% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/os-emergency-services-gazetteer/os-esg-technical-specification/code-lists/classificationcode.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.