As users are added to PolicyTech, the administrator decides which sites each user should have access to. When you assign a writer, reviewer, approver, or assignee to a document or questionnaire and that user is not assigned or and has not been given access to the site containing the document/questionnaire, PolicyTech lets the user open the document /questionnaire anyway in order to complete the assigned task. However, the user can only open the document/questionnaire from the task in My Tasks or from the link in the notification email. The document/questionnaire cannot be found using Search or Browse, 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/questionnaire that the user should not have access to.