A (proprietary) HTML attribute I'm keen to add to links is `modal`. I'll let you set this to "overlay", "aside", "above", "below", "leftside", "rightside", "aside", "top", "left", "bottom", or "right" to present the linked page as a modal dialog in the specified location. In relation to the link or not.
Mostly as a concession in my fight against overlays! Which are annoying us all.