***** urls

#% markdown
<http://daringfireball.net/projects/markdown/>
<http://daringfireball.net/projects/markdown/syntax>
<http://daringfireball.net/projects/markdown/basics>
<http://en.wikipedia.org/wiki/Markdown>
<https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet>
<http://whatismarkdown.com/>

Markdown supports two styles of headers, Setext and atx
Setext
<http://docutils.sourceforge.net/mirror/setext.html>
<http://en.wikipedia.org/wiki/Setext>
atx
<http://www.aaronsw.com/2002/atx/intro>

<http://support.iawriter.com/help/kb/general-questions/markdown-syntax-reference-guide>
<http://bywordapp.com/markdown/syntax.html>
<http://stackoverflow.com/editing-help>

<http://support.mashery.com/docs/customizing_your_portal/Markdown_Cheat_Sheet>
<http://warpedvisions.org/projects/markdown-cheat-sheet.md>
<http://nestacms.com/docs/creating-content/markdown-cheat-sheet>
<https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet>

<https://help.github.com/articles/github-flavored-markdown>
<http://lifehacker.com/5943320/what-is-markdown-and-why-is-it-better-for-my-to+do-lists-and-notes>

#% pandoc markdown
<http://johnmacfarlane.net/pandoc/demo/example9/pandocs-markdown.html>
<http://johnmacfarlane.net/pandoc/README.html>
<http://johnmacfarlane.net/pandoc/demo/example19/Pandoc_0027s-markdown.html>
<http://johnmacfarlane.net/pandoc/>
<http://johnmacfarlane.net/pandoc/epub.html>
<http://johnmacfarlane.net/pandoc/faqs.html>

#% multimarkdown
<http://fletcher.github.io/peg-multimarkdown/>

#% markdown pandoc v multimarkdown
<https://github.com/jgm/pandoc/wiki/Pandoc-vs-Multimarkdown>

#% rST v markdown
<http://stackoverflow.com/questions/34276/markdown-versus-restructuredtext>

***** rb file
lib/sisu/v6/txt_markdown.rb

***** transformations :transformations:markup_markdown: #%
#% structure - headings, levels
  [] sisu (A-C, 1-3)
  [] collapsed (1-6) (decoration)
    [inline 1-5]
      '#'
      '##'
      '###'
      '####'
      '#####'
      '######'
    [underscore 1-5]
      '='
      '-'
      #'~'
      #'^'
      #'+'
  [] node (child, parent ...)

#% font face
  [open & close marks]
  [] bold
      '**'
  [] italics
      '*'
  [] underscore
      ''
  [] superscript
      ''
  [] subscript
      ''
  [] strike
      ''
  [] add
  [] monospace
      '`'

#% para
  [] default
  [] indent
    [] default, all
    [] first line hang or indent further
  [] bullet
      '*'
  [] numbered list
      '0.'

#% blocks
  [] code
    '    ' #indent at least 4 spaces
    [] [type of markup if any]
  [] poem
  [] group
  [] alt
  [] tables

#% notes
  [] footnotes
    [] [bibliography?]

#% links, linking
  [] links - external, web, url
  [] links - internal

#% images [multimedia?]
  [] images
    [] [base 64]

#% object numbers
  [] ocn (object numbers)

#% contents
  [] toc (table of contents)
  [] index (book index)

#% breaks
  [] line break
  [] horizontal rule
      (three or more asterisks hypens or underscores)
      * * *
      ***
      *****
      - - -
    ___
  [] column break
  [] page break

#% misc