Ah, yes. There is a whitelist. Even though the book website is 'public' it hasn't really been advertised (apart from the initial "Hey, we're writing a book!" a

Ah, yes. There is a whitelist. Even though the book website is 'public' it hasn't really been advertised (apart from the initial "Hey, we're writing a book!" announcement [1]). There were already lots of reviewers for the alpha stages so not much need to attract more. The beta stage might be different as the early 'bugs' will have been squashed so that phase of writing might take a different approach. [1] https://news.ycombinator.com/item?id=3641355 https://news.ycombinator.com/item?id=3641355