anchor.diff:  |path^[2]^ {vbar} image macro^[3]^
   |:title-page-background-image: image:title-bg.jpg[]
   
  -|toc-max-pagenum-digits^[9]^
  +|toc-max-pagenum-digits^[10]^
   |Integer (default: 3)
   |:toc-max-pagenum-digits: 4
   |===
  
positive.code: . Controls whether the implicit `page-number` attribute is to the running header and footer content specified in the theme file.
  Instead of disabling page numbers, you can use the `noheader` and `nofooter` attributes to disable the running header and footer, respectively.
  . Enables generation of the http://milan.kupcevic.net/ghostscript-ps-pdf/#marks[pdfmark] file, which contains metadata that is fed to Ghostscript when optimizing the PDF file.
  . _(Experimental)_ The `text-align` document attribute is intended as a simple way to toggle text justification.
  The value of this attribute overrides the `base-align` key set by the theme.
  For more fine-grained control, you should customize using the theme.
  
negative.code: |flag (default: _not set_)
  |:pdfmark:
  
  |scripts^[7]^
  |cjk (default: _not set_)
  |:scripts: cjk
  
  |text-align^[8]^
  |<<text-alignments,Text alignment>>
  |:text-align: left
  
  