The canonical handle will always point to the newest version of an Item. This makes sense if you hide the version history. Normal users won't be able to find older versions and will always see just the newest one. Please keep in mind, that older versions can be accessed by "guessing" the versioned Handle if you do not remove the read policies manually. The downside of this identifier strategy is that there is no permanent handle to cite the currently newest version, as it will get a new Handle when a newer version is created.
With DSpace 6, versioned DOIs (using DataCite as DOI registration agency) were added added and the default versioned Handle strategy was changed. Starting with DSpace 6 the ,
VersionedHandleIdentifierProvider creates a handle for the first version of an item. Every newer version gets the same handle extended by a dot and the version number. To stay by with the example from above, the first version of an Item gets the Handle 10673/100, the second version 10673/100.2, the third version 10673/100.3 and so on. This strategy has the downside that there is no handle always pointing always to the newest version. But each version gets an identifier that can be use to cite exactly this that version. If page numbers changes change in newer editions, the old citations stay valid. This strategy makes sense, especially if you present the version history to all users. In the image below you see a version history using this strategy.
In DSpace 4 and 5, only the strategy using canonical handles (one handle that always points to the newest version) were was implemented. In DSpace 6 the strategy of creating a new handle for each version was implemented . With DSpace 6 this new strategy become and became the default. The strategy using the canonical handle still exists in DSpace but you have to enable the
VersionedHandleIdentifierWithCanonicalHandles in the file
[dspace]/config/spring/api/identifier-serice.xml. With DSpace 6, versioned DOIs were introduced using the strategy that every new version gets a new DOI (extended by a dot and the version numbers for versions >= 2). To use versioned Handle DOIs, you have to enable DOIs, you have to use DataCite as the registration agency, and you have to enable the
VersionedDOIIdentifierProvider in the named configuration file.