As users are added to PolicyTech™, the document control administrator decides which sites each user should have access to. When you assign a writer, reviewer, approver, or reader to a document and that user is not assigned or and has not been given access to the site containing the document, PolicyTech lets the user open the document anyway in order to complete the assigned task. However, the user can only open the document from the task in MY TASKS or from the link in the notification email. The document cannot be found in the document list, since the user cannot select that site.
Keep this in mind as you assign users from other sites. Be sure that you're not granting a user access to a document that the user should not have access to.