While a design is open in the Editor, you can create annotations. Any project member can view the annotations, but only users with Developer privileges or better can create them.
To create an annotation, follow these steps:
1. Select Annotate tool
Click the Annotate button in the Editor toolbar, or use the keyboard shortcut.

Annotate Mode
2. Create an annotation
Click anywhere on the design to create an annotation. The New Annotation dialog opens. Specify the subject and, optionally, a description and on-click actions. A marker is created and the annotation appears in the Annotations pane in the Sidebar. Note that you can drag the marker to any position within the design.
3. Leave Annotate mode
When you’re finished creating annotations, press the Escape key to return to using the Select tool.