Rewriteable media, such as magnetooptic record members or disk has its recording controlled such that the recording is certifiable as meeting write once read many characteristics. Controls are introduced for the entire disk for indicating that the rewriteable disk is to be used for certified or vault writing, at least in some radial zones of the disk. Recording or writing operations are limited to those addressable areas on the certifiable rewriteable medium that have not been previously written. Each of the addressable areas of the medium, in a disk termed, sectors, have a precursor portion called a control area which indicates the status of the sector and is used for preventing overwriting or erasure as well as controlling.