You can add comments to viewpoints, viewpoint animations, selection and search sets, clash results, and TimeLiner tasks.
Review tools (redlines and tags) enable you to add annotations to viewpoints, and clash detection results. The Clash Detective feature is available for Autodesk Navisworks Manage users only.
Using review tools is mutually exclusive to using navigation tools (see Product-Specific Navigation Tools), so that when you add redlines or tags you cannot navigate and vice versa.