External links are marked with the "external" class, and get target="_blank" set.

Currently, the CSS class causes the links to get an icon indicating that the link is external or opens in a new tab respectively.

To improve accessibility, we would like to add a title on all external link, which we could then reference in CSS via attr():

<a href="external" title="External link (opens in new tab)">…</a>

The title could come from https://github.com/mdn/content/blob/main/files/jsondata/L10n-Template.json.