We disable students when they drop. Every so often, we're asked to re-enable the enrollment because the student is auditing. We would use the University of York DSK tool to re-enable the enrollment and shift the enrollment DSK to SYSTEM (so our legacy snapshot wouldn't touch it).
If we create the STORE/DELETE pair of files, the student drop will appear in the DELETE.
I did some quick testing of the following scenario: if student drops, then gets overridden (put into SYSTEM DSK) to be re-enabled, will the DELETE feed disable them again?
The short answer is YES. If you happen to re-process the DELETE feed that originally dropped the student, the student will get disabled, regardless of DSK.
Tim Grady mentioned a workaround at the developer office hour, but I wasn't clear what the workaround would be to protect a student who's been re-enabled but in SYSTEM DSK.