2 variables are related to the upgrade of files of previous version to the current.
It is important because when a file has been upgraded to a newer version it can not be modified anymore using the previous.
For example, the objects schema has changed from 2019-R2 to 2020-R1 (no change from 2020-R1 to 2020-R2).
If you open a 2019-R2 file in 2020-R1 (or R2) you want to control if it could be upgraded or not.
Variables are: