Still, I'm not swayed. I would rather have the current mechanism, which allows me to deal with the syntactic and semantic differences on a browser by browser

Still, I'm not swayed. I would rather have the current mechanism, which allows me to deal with the syntactic and semantic differences on a browser by browser basis. The current situation is an escape valve for the inevitable flux & lag between the standards process and implementation compliance. If you invent a universal prefix you no longer have as much of an escape valve...you just have a namespace where you accept random non-compliance. And if you're ok with one such namespace, then why not one for each rendering engine, so that they're at least compartmentalized a bit?