long-term preservation

Preservation and management of documents for a long period of time, such as 30 or 100 years, under predetermined preservation conditions.

Both preservation conditions and the preservation period are determined by laws and regulations, business necessity, historical value, etc.
The length of time considered a "long-term" period varies depending on the management system or medium. The JIS Z 6017 defines long-term as around 10 to 30 years for optical disks, and JIS Z 6018 defines long-term as 100 years or more for microfilms.