Target="_blank" attribute add to external links.

Remove tag until the

Interestingly, the original IS requested the opposite of the current scope and accessibility best practice. Updating the IS to avoid confusion.

This is at least wrong in core everywhere the string the documentation for PHP date formats appears, and in the empty text for the frontpage view. And maybe the announcements feed.

Better scope.

Thanks for updating this @xjm.

We do indeed want to remove the target="_blank" attribute where we can.

Tag cleanup. (We don't actually need a11y review right now, and I did the IS update.)

I guess whether or not the date format links should open a new window is debatable, because technically they could be on a multistep form. I would still lean toward removing them. We can probably have an accessibility maintainer give feedback on that once we've identified the full scope of what core does.

A novice could work on this. The next step on the issue is to search for all the uses of target="_blank" in core, and document a list of which category the fall under as I've outlined them in the issue summary. Pay careful attention to the instructions in the issue summary.