Product IDs and Uniqueness

Product IDs

It is possible that product IDs can be identical between, for example, a standard MultiNet feature ID and a MultiNet enhancement product feature ID located in the same geographical location. Many record types have fields where an ID-number of a particular entity is declared, or that refer to the ID-number of an entity declared in another record. These ID-numbers are unique within a given context (e.g., Section, Data Set).

Within the same context, no two entity instances of the same type (e.g., Feature Category, Road Element Name) have the same ID-number.

Feature Representation

One feature that can have different representation possibilities (water line and or water area) requires uniqueness across representations.

A water line and water area representing the same section of water do not share the same ID.

GDF

The GDF model requires identifiers to be unique within their feature class:

(point, line, area, complex relationship) per layer (not across layers);
(node, edge, face) per layer (not across layers).