Index Numerator
Index Numerator is a special mechanism for sequential numbering. It provides a numbering the collection of referenced objects in the context of its owner. Unlike the Business Numerators, Index Numerator is intended for the Int32 properties.
The image below shows Document and Position objects. Referenced Position objects are numbered separately for each Document owner.

This mechanism effectively numbered hierarchical objects according to the level at which they are located. At each level of the hierarchy objects are numbered separately.

Index Numerator supports XAF ModuleUpdater and direct queries to the database. The component provides an API that allows you to move objects to the top/bottom/random position in the collection and automatically recalculate numbers (see Examples).
For more information, refer to the following documents: