Keyboard interaction
All focusable interactive elements are operable with a keyboard and can be navigated to and from using the Tab key
Why it matters
All interactive elements on a page (e.g. fields, buttons, links, menus, accordions, media players, etc.) need to be operable with the keyboard. We also need to ensure that keyboard users do not become trapped in a subset of the content that can only be exited using a mouse or pointing device. For example, keyboard users must be able to use modals, lighboxes, and other pop-ups, and dismiss them with the Escape key.
WCAG 2.0 reference: 2.1 Keyboard Accessible (Guideline), 2.1.1 Keyboard, 2.1.2 No Keyboard Trap
Example: When a modal dialog box is triggered, it needs to “trap” the keyboard use to the modal until it is dismissed by the user. The keyboard focus needs to immediately move to the first actionable element in the modal. When a user moves the keyboard focus past the last element in the modal dialog box, it needs to loop to the beginning of the dialog box. The keyboard user needs to be able to access all controls in the dialog box, especially the controls to dismiss the dialog.
How to check for this
Follow these steps Manual
Collaborators
Designers identify and define the tab order