anchor.diff:  
   |title_page_logo_image
   |inline image macro
  -|logo_image: \image:logo.png[scaledwidth=25%]
  +|+logo_image: image:logo.png[scaledwidth=25%]+
   
   |title_page_logo_top
   |percentage
  
positive.code: 
  |page_background_image
  |path (absolute or relative to pdf-stylesdir)
  |background_image: \image:watermark.png[]
  
  |page_layout
  |portrait, landscape +
  
negative.code: 
  |title_page_background_image
  |path (absolute or relative to pdf-stylesdir)
  |+background_image: image:title.png[]+
  
  |title_page_logo_align
  |left, center, right
  