Each and every feature within OS MasterMap has the TOID (TOpographic IDentifier) as a unique reference. This makes it possible to identify any single feature within the dataset without any ambiguity.
Current referencing systems, such as coordinates and addresses, are subject to interpretation between users. This creates fuzzy matching issues between organisations wanting to exchange data; for example, will the building St James House be picked up in another system where it is spelt St James' House?
TOIDs will stay the same throughout the life cycle of each feature. In other words, if a feature changes, the TOID will stay the same as long as it is deemed to be the same feature; for example, a house having an extension built is still the same house and fulfils the same purpose. This provides a continuity of reference even though a feature may undergo changes. This makes the TOID a robust referencing system that customers can use alongside, or instead of, their own referencing systems and can link to their own information about the feature. Having unique references is essential to making the most out of storing data within a relational database management system, as these rely on unique referencing to be able to store, sort, manage, query and retrieve data efficiently.