[eithed]

>To add insult to the injury, named elements are accessible as global variables only if the names contain nothing but letter.

This doesn't seem to be true as shown within this fiddle: https://jsfiddle.net/L785cpdo/1/

Bear in mind that only undefined elements will be declared this way

[mmazzarolo]

Author here. That was a mistake on my part, it shouldn't have slipped in :) I removed that section, thanks for reporting!