Safeguard’s PDF protection enables you to control PDF expiry to groups of documents (publications) on an individual user basis. Different users will often require document access at different times (and for access to expire accordingly) depending on when first purchased a product (say a training course) or when they were first given access to documents.
A user for example, may have subscribed to one of your publications for a year, and all documents in that publication are accessible to them for a year. After a year, they will still be able to view their existing documents, but not any new ones that are published after their subscription period has ended, unless of course they subscribe for an additional period.
Users can be given access to multiple publications, each with their own expiry period.