Ahh... for XHTML, it's needed. HTML5 not needed. Since the templates use XHTML 1.0 Transitional, I've added that to the script.. thanks again.
BTW, it was an interesting challenge to modify Curly's original Google map script to do Leaflet instead .. a bit of somewhat convoluted PHP to generate the inline script only if the alert had geo-coordinates present, and quite a change in the generated JavaScript to control Leaflet due to differently named/accessed Leaflet functions v.s. Google maps functions.
Posted in the usual places...