Avoid Pop-ups and Links Opening in New Windows
WAI Definition (Checkpoint 10.1)
Do not generate pop-ups or new windows and do not change the current window without informing the user.
Do not create pop-ups (windows that automatically open).
Do not open links in new windows without informing the users.
Pop-ups can be very frustrating for users and many people find them annoying. Pop-ups can also erode a user's trust in a site as it affects their control over the navigation and interaction.
Furthermore, pop-ups are known to cause problems for screen-reader users because they change the focus without warning. This means that the screen reader begins reading the content of the new window, usually without warning the user that a new window has opened. If the new window displays content from another site, the user can become very disoriented and confused.
Pop-up windows used to display an error message in a form can cause problems too. The user has to read the content of the pop-up window, navigate back to the main page, and then find the relevant position on the form again before they can fix the error.
Avoid opening links in new windows.
If you open a link a new window, add a warning in the link title, including a message like "(this will open in a new window)". Including the warning as part of the hyperlink makes the link title more meaningful when read out of context, e.g. it will be read by screen-reader users when they call up a list of links on the page.
<a href="un.org" target="_blank">United Nations homepage (this link will open in a new window)</a>
Using the Firefox Web Developer's Toolbar (plugin):
Go to Information > View Link Information.
Links should not have the attribute 'target="_blank"'. If they do, the users should be warned that the link will open in a new window.