data-hint attribute and gets displayed when hovered over.
I was facing a problem today where I had to display a tooltip with multiple lines. At first it seemed impossible to add line breaks to the content of an attribute. But after reading up on it for a bit I found a way that worked very well for me.
I inserted the line break via an entity like this:
<a href="page.html" data-hint="One line And another line">My link</a>
and added a
white-space: pre to the pseudo element that represented the tooltip. Et voilà: multiline tooltips. That’s what I learnt today.