The "Sharing" tab is now a global action
The "Sharing" tab now points to the '@@sharing' view, and is defined as a global action in the 'object' category. If you have a custom content type and you have set up the 'local_roles' action, which would normally be pointing to the 'folder_localrole_from' template, you should remove it. It will be removed from existing, installed types during migration.
If you do not remove the action, the user will see two "Sharing" tabs.
For an example of the canonical set of actions and aliases, see "the GenericSetup definition of the Document FTI":http://dev.plone.org/plone/browser/CMFPlone/trunk/profiles/default/types/Document.xml. Of course, you may not need the 'References', 'History' or 'External Edit' actions in your own types.

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