A reader follows a link and presses Back, only to discover that they are in a new tab. The link worked technically, but its behaviour was not clear before activation.
W3C technique G201 describes giving advance warning when a control opens a new window or tab. It is advisory guidance, not a statement that this particular technique is mandatory for every WCAG success criterion.
First decide whether a new tab is needed
Leaving ordinary navigation in the current tab lets people use familiar browser controls and choose a new tab themselves when desired. If your design deliberately opens another context, provide a cue before the action rather than explaining it after the page appears.
A straightforward label could be “Annual report — opens in a new tab.” If an icon is used, make sure its meaning is available in text to people who cannot perceive the icon. An unexplained arrow is not a universal vocabulary.
Test what the person actually encounters
Navigate to the link with a keyboard and inspect its accessible name or description. Confirm that the warning is available before activation and that the destination behaves as described. Do not assume a tooltip that appears only on mouse hover is enough for everyone.
- Keep the destination’s purpose clear.
- Avoid repeating a long warning inside every nearby sentence.
- Use consistent cues for the same behaviour.
- Check that the implementation does not produce duplicate announcements.
For an invented form example, opening help in another tab may preserve an unfinished form. Test whether that preservation actually works; a new tab should not be used as a substitute for reliable form state handling.
Include the behaviour in usability testing with the rest of the task. The goal is not merely to add words beside a link, but to let people understand where the action will take them and how to return.