Click Validate at the bottom of the Validate sidebar to turn validation on or off. When validation is on, errors and warnings will appear both in the sidebar and as warning icons in the line number gutter of the document being edited. This allows you to continue to see the results of validation even if you switch away from the Validate sidebar.
Click the warning triangle at the bottom left corner of the Validate sidebar to turn warnings on or off. If warnings are turned off, only errors in validation will be displayed.
Clicking on a validation error in the sidebar will highlight the part of your document that the error refers to, and display the full text of the error at the bottom of the sidebar.