Tape Backup Wizard: Retention

Specify how many recovery points you need to be copied by the job. Use the following options:

Keep all recovery points forever: All available recovery points will be copied by the job. To set a different retention policy, deselect this option and choose one of the options below.
Keep X last recovery points: Keeps the specified number of last recovery points for each machine in the job.
Keep one recovery point per day for X days: Keeps one last recovery point per day for the specified number of days.
Keep one recovery point per week for X weeks: Keeps the last available backup of every week for the specified number of weeks.
Keep one recovery point per month for X months: Keeps the last available backup of every month for the specified number of months.
Keep one recovery point per year for X years: Keeps the last available backup of every year for the specified number of years.

For an example of job retention settings and further explanation, refer to the Keeping Recovery Points Knowledge Base article.