I got about halfway through this before I decided that I just wanted to see the final result. Perusing the source of the final link, I saw a bunch of unclosed tags - is this something that he mentions is allowed in HTML5? I don't think I could bring myself to place unclosed <p> or <td> elements in my page.
As a side note I submitted this post while not logged in, was redirected to the login page, came back to my post and instead of showing "<p>" the input field had rendered a newline. Vulnerability of some sort?
I've touched up the example source a bit to be closer (in style) to the original. I may want to talk about "which tags implicitly close others" but that's not the subject of this chapter, and having unclosed tags in the example source is distracting from the main point.
"which tags implicitly close others" - stuff like this makes me cry. What is the benefit of a format that allows such complicated rules for parsing the document? Flexibility like this on the input is just increasing complexity of the rendering engines and ambiguity of the resulting output.
As a side note I submitted this post while not logged in, was redirected to the login page, came back to my post and instead of showing "<p>" the input field had rendered a newline. Vulnerability of some sort?