Below is a simplified look of a basic HTML document used in ebook formatting. (unrulyguides.com)
However, I did notice one flaw in document rendering: The blockquote tag in HTML documents is not properly indented. (computerworld.com)
But ePub does not support special formatting, tables, and large illustrations, so until the iPad can do the same thing it does with html documents and visual displays it will behave just like any other reader. (lulu.com)