The Details area for a ClassificationScheme object contains the following additional fields:
External Classification Scheme checkbox. This checkbox is selected if the classification scheme is defined outside the Registry (that is, if it has no concepts). An internal classification scheme is a classification scheme whose concept hierarchy is defined within the Registry.
The Value Type menu, which contains one of the following selections:
Unique: This value indicates that each node of the taxonomy has a unique code assigned to it. This value is the default when you create a classification scheme in Service Registry.
EmbeddedPath: This value indicates that the unique code assigned to each node of the taxonomy also encodes its path.
NonUnique: In some cases nodes are not unique, and it is necessary to use the full path (from the ClassificationScheme to the node of interest) to identify the node. For example, in a geography taxonomy, Moscow could be under both Russia and the USA, where five states have cities that are named Moscow.