Folder Policy Properties: Retention Category

The page shows the Retention Category that is used for all items that are archived under this policy.

Use Volume Policy settings (available only on folder policy properties). Select this to use the Retention Category that is defined in the volume policy. Clear Use Volume Policy Settings if you want to select a specific Retention Category for the folder.

Any change you make is not retrospective; the change applies only to files that are archived after you apply the change.