The NHS digital service manual provides guidance on using expanders, a UI component that allows users to reveal more detailed information on a page. Expanders are useful when the content is overwhelming, intended for a wide audience, and there is a clear user need. However, they should be avoided if only some users need the information, for form help, or on pages with other interactive elements.

The manual explains how expanders work, including the option to have multiple expanders on a page. It emphasizes the importance of using clear, descriptive link text so users can quickly determine if they need to click. The guidance is based on user research testing expanders on pages about health and medicines, where users felt the information was too much.