They are talking about the Lime Green Mickey Heads you get from Home Depot (paint display). It's the universal symbol for a disboarder.
I peel mine off (with out water) and then put them back to back. I usually write my dis name on both sides. For quick lamination you can use clear mailing tape. It's not 100% percent water proof but I've found that the peel and stick laminating things aren't either. Then I punch a hole in the top and hang it from things. Sometimes it's on my purse, stroller (if we have one), etc. In a pinch I'll use one of my DD's pony tail holders and a safety pin to hang off my messenger bags zipper.
HTH.