a lot of websites (including https://www.eff.org/) hide the web labels link anyway with CSS. So why don't let people use a link-tag as an alternative to an a-tag to specify their web labels page, in case they don't want have a visible link? We can't force them to show the link anyway, but hiding it with CSS looks like a hack, since that is what the link-tag is for. You find the patch in the attachment.
link.patch