Schema.org Déjà vu

The Web has been around for getting on for a couple of decades now, and massive industries have grown up around the magic of making it work for you and your organisation.  Some of it, it has to be said, can be considered snake-oil.  Much of it is the output of some of the best brains on the planet.  Where, on the hit parade of technological revolutions to influence mankind, the Web is placed is oft disputed, but it is definitely up there with fire, steam, electricity, computing, and of course the wheel.  Similar debates, are and will virtually rage,