This code list is used in association with the Extent Definition attribute which is present within the Named Area Feature Type. The code list describes how the named area extents are defined by Ordnance Survey.



Auto-Generated Indication

This means the extent geometry is a convex hull around one or more items of cartographic text, and so provides a minimal extent. Long term these will be prioritised and improved as necessary. For Named Hill Or Mountain and Named Spot Height features, this means that the extent geometry is a dodecagon of radius 100m. Ordnance Survey does not have any plans at the current time to capture full extents of these features, because of the difficulty in defining where one hill or mountain stops and another begins.

Manually Defined Complete

Captured manually by Ordnance Survey through a combination of assessing the surrounding geographic features that give context to the name, reviewing text positioning on existing and historic products, reviewing historic documentation from when the names were originally collected and by consulting recognised expert sources. These features have inherently fuzzy boundaries. The geometries can be updated on the basis of intelligence from recognised expert sources, but not in response to individual queries on where the boundaries should be.

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