Multiline Tooltip

I’m playing around with the Small World module to get a feel for the module editor, and one of the things I’d like to do is display brief descriptions of the various race/power abilities as tooltips when you hover over the relevant piece. I can do this with the Mouseover Stack Viewer and a Marker trait, but the descriptions are much too long for a single line - so I was wondering if anyone knows how to line break a tooltip. I tried enclosing the Marker value in HTML tags, but no dice - any ideas?

Holy crap I don’t know how I missed JoelCFC25’s post about this exact issue last month, after all the searching I was doing looking for an answer. Mods, please remove, thank you!

But I really would like to know still…