Each namespace has a default retention setting. This is the setting applied to an object when it is stored in the namespace unless the retention setting is explicitly specified in the request to store the object. After an object is stored, users can change its retention setting (subject to the rules for changing retention settings).
When you create a namespace, its default retention setting is Deletion Allowed. Objects with this retention setting can be deleted at any time except when they’re on hold.
You can change the default retention setting for a namespace at any time. Changing this setting does not affect existing objects in the namespace.