--- HTML
<h1>Some header</h1>

<p>Some <b>te<i>xt</i></b><i> and italic</i></p>
^ Overlapping markup is hard!

--- Heirarchy

h1. Some header

p. Some
  b. te
    i. xt
  i. and italic

--- Raw text
Some header\n
\n
Some text and italic

Standoff properties:
[
  {
    markType: 'heading',
    startOffset: 0,
    endOffset: 10,
    author: 'jess'
  },
  {
    markType: 'bold',
    startOffset: 17,
    endOffset: 20,
    author: 'john'
  },
  {
    markType: 'italic',
    startOffset: 19,
    endOffset: 27
  },
  {
    markType: 'comment',
    startOffset: 15,
    endOffset: 19,
    commentText: 'This word "some" at the beginning of the line is silly'
  }
]

Separation of semantics from content!
Many different layers of semantic meaning.
Enables multiple authors to overlay their semantics