The licence file ID is a counter which is increased every time a new licence file is created. The counter is stored in the project template in the field <NextLicFileKey>.

 

If you use the project files in different locations, use per location a different range of values.

 

Example:

 

 

As the licence file ID is also used to track time limitation on a PC, just make a new licence file for a new release to allow that a user can test the application again.