Yeah, whatever custom versioning scheme you were using on 9.1 needs to be loaded into 10.2.
A sample is shown in the knowlege base here:
https://support.ptc.com/appserver/cs/view/solution.jsp?n=CS23066
Another discussion here:
https://support.ptc.com/appserver/cs/view/solution.jsp?n=CS53009
Fully documented in the Specialized Administration Guide
