The design view in Visual Studio can display the start tag and end tag of the hidden non - graphic elements (such as div, comments, span, form, line breaks and script elements). This feature helps to see where the elements are and avoid unknowingly deleting the non-graphic elements from a page while editing.
To enable it open an aspx page and follow the following steps:
1. Click on "View"
2. Click on "Formatting Marks"
3. Click on "Show"
4. Repeat step-1 and step-2
5. Click on "Tag Marks"
