With this attributes decorating the Properties of a Web Part...
[WebBrowsable(true)]
[Category("Common Settings")]
[WebDisplayName("Show tab header")]
[WebDescription("Show tab header for the News Feed webpart")]
[Personalizable(PersonalizationScope.Shared)]
... is the [WebPartStorage(Storage.Shared)]
implied when using the above attributes (PersonalizationScope.Shared)
, or are the value stored for each user if Storage.Shared is not explicitly set.