I don't know either but to find out I would;
Export a small Sequence with a Job activity with the option run.
Change the Sequence to reset then run and re-export.
diff the two.
The difference (the change from run to reset then run) "should be" fairly easy to discover.
Look for the Execution Mode provided in the .dsx file. It is 0 for Run and 1 for reset and run.
Also there is a check like the following
If Not(b$CPRestarted) Then GoTo L$V0S3$PREPARED
for the simple run option, which needs to be removed for reset and run.