Prerequisites axe DevTools grunt Moodle instance's developer mode turned on Test Install the axe DevTools. Open your browser's "Manage extensions" page. Open the details for the axe DevTools. Make sure that its "Allow access to file URLs" setting is enabled. On a terminal, go to your moodle instance's root directory. Run " grunt componentlibrary ". On your browser, go to Site administration > Development > UI Component library On the component library's page, go to Moodle > Accessibility > Links Open your browser's dev tools and go to the axe DevTools tab. On the axe DevTools interface, press " Scan all of my page " Click on the " Elements must only use allowed ARIA attributes " (there will be elements with this error until MDL-72412 gets resolved) Under the issue details window, press "highlight". Press the arrow keys near to check which UI element is being highlighted with the invalid ARIA attribute error. Confirm that the following don't get highlighted: The "Opens in new window" icon in the Moodle.org link under the " Using an image icon with alt text to indicate that the link opens in a new window " example The "PDF document" icon in the " File type indicated via an icon/image's alt text " example. The " Link leads to external site " icon under the " Links that lead to an external site " example.