[Editor's note: see more recent article by Dennis, When and How to Visually Hide Content]
There are certain instances when a label or header should be used, but wouldn’t necessarily need to be seen in the layout, such as a label for a phone number and a header for a menu. Dennis discusses when and how this would be done.
- Invisible Content Just for Screen Reader Users (WebAIM)
- Creating Invisible labels for form elements (WCAG 2.0)
- Advanced accessibility techniques – Hidden Text (WebCredible)