Library administrators can set up variant criteria to be single select or multi select. Objects can be assigned multiple values from a multi-select variant criteria. This allows authors to create objects that appear in multiple variations of a published output.
For example, ACME has a sub-book called Gas giant safety protocols. This sub-book is included in various other book objects. The Gas giant safety protocols sub-book has values from the planet variant criteria assigned to it: Neptune, Uranus, Saturn, and Jupiter. This ensures the content of this sub-book is published when any of these four values is selected for a publishing job.