2.20 For S (Security) Grade Devices, User Must Not Enable Write Protection for Protected 4 K Regions, Also Known as Special Sectors in the eNVM

For S (security) devices, there are two or four 4 KB regions per eNVM array that can be protected for read and write. These regions are known as Protected 4 K Regions or Special Sectors. If write protection is enabled for any of these regions, none of the locked pages inside the same eNVM block can be unlocked.