a system and method for encoding servo sector information in a nonvolatile data storage and retrieval system using rotating recording disks . servo sectors are angularly - spaced approximately radial regions reserved for position reference and tracking adjustment information . servo timing marks including means for detecting defects on the recording surface , encoded track address and sector address data , and position error signal blocks are permanently fabricated into a number of servo sectors . the present invention helps the storage system controller locate , certify , and follow any particular track and sector while maximizing the amount of disk surface area available for data storage and retrieval .