anchor.diff:  
   |title-logo-image
   |path^[2]^ {vbar} image macro^[3]^
  -|+:title-logo-image: image:logo.png[top=25%, align=center, pdfwidth=0.5in]+
  +|:title-logo-image: image:logo.png[top=25%, align=center, pdfwidth=0.5in]
   
   |title-page-background-image
   |path^[2]^ {vbar} image macro^[3]^
  -|+:title-page-background-image: image:title-bg.jpg[]+
  +|:title-page-background-image: image:title-bg.jpg[]
   |===
   
   . `<face>` can be `front` or `back`.
  
positive.code: 
  |page-background-image^[4]^
  |path^[2]^ {vbar} image macro^[3]^
  |+:page-background-image: image:bg.jpg[]+
  
  |pagenums^[5]^
  |flag (default: _set_)
  
negative.code: |<face>-cover-image^[1]^
  |path^[2]^ {vbar} image macro^[3]^ +
  (format can be image or PDF)
  |:front-cover-image: image:front-cover.pdf[]
  
  |media
  |screen {vbar} print {vbar} prepress
  