Viewer.ReviewerMarkupVisible Property (Visio Viewer)
Gets or sets a value that indicates whether markup of the specified reviewer is visible in the drawing that is open in Microsoft Visio Viewer. Read/write.
The collection of reviewers is one-based, so the index of the first reviewer in the collection is 1. The default is for reviewer markup to be visible for any reviewers in the drawing. If there are no reviewers in the drawing, or if you pass the index of a nonexistent reviewer, Visio Viewer returns an error.