For each Global Substitution batch job, you can specify whether or not to check in all locking units when the job completes.
Because the Global Substitution tool does not perform any validation, it is possible that a batch job could make changes to structured documents that are not valid.
By leaving the Check In box cleared in the dialog, you can leave all locking units checked out when the job completes. You can examine and validate each changed object, make any needed changes, and check them in manually, or revoke the edit and discard the changes.
If you select the Check In box in the dialog, all objects will be checked in to the repository when the batch job completes. For some batch jobs, this might be the most efficient choice if the job does not modify structure. Also, if you have tested the Global Substitution rules in a test environment and are confident you will not create invalid structure, you might want to select this option. There is no option to undo the changes. If you check in changes that you want to discard, you can roll forward the previous version of each object.