Notes

Backup media itself can become corrupt or simply lost.

You should maintain at least three sets of backups, so that the chances of not having at least one reliable backup are minimised. The backup "Generations" should be used in rotation, ie Backup on media set A, then B, then C, then back to A, then B, then C etc.

It is recommended you hold at least 3 generations of backups, but even more is an advantage.

It is also recommended you complete a separate Monthly Backup in addition to regular backups. This backup should be held off-site, and preferably never be overwritten, ie. it is a permanent record held forever (or as long a the media is permanent).