Of a recording medium, erasing or overwriting all data in such a manner that it cannot be recovered, even by extraordinary, e.g., laboratory, means. Note: Sanitizing is distinguished from simply "deleting" or "erasing" data. For example, a software-based deletion command may simply mark a file or block of data to the effect that it may be overwritten during a subsequent "save" of different data. Until such a save is performed, the deleted data may be recovered, sometimes by the simple expedient of executing a software command. Likewise, digital data, for example, may be "erased," from a magnetic recording medium, but still be recoverable if subjected to laboratory techniques that can identify residual magnetism left after the erasure.