Mark and treat plone content as outdated
slc.outdated provides an object action for plone to toggle an outdated flag on any object that is IAnnotatable. The value of the flag is stored in an annotation, indexed in the catalog via an indexer and included in the metadata.
By that you can use it for catalog queries and e.g. set CSS classes accordingly.
A viewlet will appear below the title of outdated content, indicating that this content is outdated. Further, the acquisition chain will be consulted for "outdated_info" and if found, its title and text body will be displayed. It should be published and hidden from the navigation.
The software is tested manually and fully functional. The lack of tests I consider a bug. I'd be most grateful if you donate tests, in case you plan on using slc.outdated.