The ID (Key) is a unique identifier for each item within Contour.  This ID(Key) cannot be duplicated.  Set Key can be changed by right-clicking on a set and selecting the 'Change Set Key' option.

 

Notes:

 

-Version 3.1.x and beyond allows administrators to change the ID of a set of items as needed, an Item Type ID is still configurable, but it only acts as a template for the set ID.  Version 3.1.x allows for backward compatibility with IDs in versions of Contour prior to 3.0.x, however, a project ID key will still be appended to the front of legacy keys.