anchor.diff:      margin_bottom: 5
   |===
   
  -. Page backgrounds do not currently work when using AsciidoctorJ PDF.
  +. Page background images are automatically scaled to fit within the bounds of the page.
  ++
  +NOTE: Page backgrounds do not currently work when using AsciidoctorJ PDF.
   This limitation is due to a bug in Prawn 1.3.1.
   The limitation will remain until AsciidoctorJ PDF upgrades to Prawn 2.x (an upgrade that is waiting on AsciidoctorJ to migrate to JRuby 9000).
   For more details, see http://discuss.asciidoctor.org/Asciidoctor-YAML-style-file-for-PDF-and-maven-td3849.html[this thread].
  
positive.code: . `<face>` can be `front` or `back`.
  . The path is resolved relative to base_dir.
  . The target of the image macro is resolved relative to `imagesdir`.
  . Controls whether the `page-number` attribute is accessible to the running header and footer content specified in the theme file.
  Use the `noheader` and `nofooter` attributes to disable the running header and footer, respectively, from the document.
  . 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.
  
negative.code: |https://github.com/prawnpdf/pdf-core/blob/0.6.0/lib/pdf/core/page_geometry.rb#L16-L68[Named size^] {vbar} <<measurement-units,Measurement[width, height]>>
  |:pdf-page-size: 6in x 9in
  
  |pdfmark^[6]^
  |flag (default: _not set_)
  |:pdfmark:
  
  |text-alignment^[7]^
  |<<text-alignments,Text alignment>>
  |:text-alignment: left
  
  