What to the numbers after an object name in a ROOT file indicate?

For example, I might create a ROOT file example.root, and store in it a single TNtuple with name “N”. If I were to then open example.root in a TBrowser, for example, I may find that “two” TNtuples are listed, “N;somenumber” and “N;someothernumber” (e.g. maybe something like N;1 and N;37).

What do these numbers indicate?


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ROOT Version: Not Provided
Platform: Not Provided
Compiler: Not Provided


These are the “cycle numbers” and they refer to different version of the same object. Such versions can be created, e.g., due to ROOT’s auto-save. The highest cycle number is always the most recent version of the object.