OS MasterMap COUs (Change-Only Updates) contain a change history attribution:
| Value | Description |
|---|---|
New
This is a new feature in the database.
Position
(Note: This is no longer used in current revision process.)
Feature has changed geometry and / or position due to an improvement in its absolute accuracy; that is, its relationship to the National Grid (relevant for the positional accuracy improvement programme which was completed in 2006). This type of feature change is not associated with real-world change.
Modified
The feature has been edited by an operator. Used in the following cases:
The geometry of a topographic feature is changed following real-world change.
The geometry of a non-topographic feature (for example, inferred link or BoundaryLine feature) is changed.
A cartographic symbol feature is repositioned.
A CartographicText feature is repositioned.
Software
Feature has been adjusted by an automatic software process. Includes geometric adjustment, cleaning, squaring, paralleling (text and lines) and reversing direction of digitising.
Reclassified
The descriptive attributes of a feature have changed. The feature code may have changed.
TextChange
Text string of text feature has changed. Applied to text features where the text string has been:
Modified for a minor change in spelling, due to original error or name change, where text string is a distinctive name.
Modified for changes to a descriptive name, due to original error or change of specification.
Modified by the addition or removal of an accent.
Restructured
New line feature(s) have been created from parts of existing feature(s). Applied to line features where:
The feature is split into two or more features.
Two or more features are joined together.
Attributes
Applied to features that have had only attributes changed, except those covered by TextChange and Reclassified values.
Incomplete
(Note: this is no longer used in current revision process.)
The feature is incomplete. Identifies an incomplete line feature or an area that relates to the incomplete feature returning from a revision process. Incomplete line features are not used to construct polygons.