DATA STRING TEMPORARY ERASING METHOD, ITS RETRIEVAL METHOD, ITS RESTORING METHOD, ITS PERMANENT ERASING METHOD AND RECORDING MEDIUM FOR STORING ADDITIONAL INFORMATION FOR RESTORING DATA STRING SEPARATED BY TEMPORARY ERASURE

摘要

PROBLEM TO BE SOLVED: To temporarily erase a data string having a packet structure through the use of locating information for restoring its original state by storing a second piece of additional information which indicates that the data string to which a first piece of additional information is added and the advanced data string are on continuous data string before erasure. SOLUTION: One piece of cell information is separated into three pieces of cell information in order to temporarily erase a part of the data string and, then, a TE flag indicating that the temporary erasure is executed is set in an intermediate cell among them for restoration afterwards. The reason why the TE flag is set is to restore the temporarily erased part afterwards. Then the TE flag indicating the temporary erasure and a CT flag indicating that the data string and the advanced data string are the one continuous data string before the erasure are stored in data string information. The CT flag means that the data string related to the CT flag and the advance data string are one continuous data string before the temporary erasure. This means that synthesization with the advanced data string is possible.