It’s a good question Ann and one that comes up regularly. Typically, reviewers would be notified by the authors, possibly sharing links to the publication in Review Space via email or other work processes internal to the customer. The RWS Professional Services team has also configured email notifications and specific review/sign off procedures within Tridion Docs as part of customer’s implementation projects. Additionally, Professional Services has also recently developed a “Review Dashboard” which is available as an add-on. It allows a Publication to be assigned a due date and set of reviewers, and a review process is then activated where the publication is visible from a dashboard UI. Individual users can then see a list of publications “in review” that they are assigned to work on as reviewers (or as the author who placed the publication into review). For more information I would recommend reaching out to your RWS Professional Services contact.