I saw this Tylenol ad the other day while flipping through the most recent issue of Real Simple magazine. I snapped it indoors with my iPhone so the quality is pretty poor, but they show the keyboard shortcut for enlarging browser text on PC and Mac.

Granted not all people needing to enlarge browser text are older users, but I've often wondered if someone like my grandma would know how to resize text, let alone be comfortably recall a keyboard shortcut.