Reference Numbers are unique to each object within Workfront. Every time an object is created, the Reference Number is incremented. Object reference numbers are assigned by server nodes which allocates groups of reference numbers at a time to work with. There is no promise or guarantee of object reference numbers being sequential because each server node takes a group of reference number sequences at a time and then uses them. Because of this behavior there can be the appearance of jumps in the reference number sequence "block" when reviewing multiple objects and their reference numbers. There also can be “jumps" in reference number sequences if other objects were entered that the user does not have access to, prior objects were deleted, or personal projects/objects were created.
There is a single set of unique reference numbers across all object types within an environment and objects are numbered sequentially across item types. There is not a way choose the starting point of the Reference Numbers sequence within an environment.
When a user creates a new object, the assigned unique Reference Number will increment from the highest existing Reference Number across all item types.
The one thing we can confirm and guarantee, is that each object will indeed have a unique reference number within an environment.