The buffer file has a syntax for the block separators, but it's human readable. Here's what it looks like:

  ∞∞∞text
  content of note 1
  ∞∞∞text-a
  note 2
  -a denotes that the block language is in autodetect mode and 
 might change
  ∞∞∞css
  .some-class {

etc...