84ff27bc___Building_IRPs_to_Perform_I_O__Purpose
[Flag] SL_OVERRIDE_VERIFY_VOLUME [Associated I/O Operation] READ/WRITE/DEVICE CONTROL [Purpose] 
For removable media, the I/O should be performed even though the DO_VERIFY_VOLUME bit is set in the driverâs device object.
The NT Insider:Rolling Your Own - Building IRPs to Perform I/O
Purpose