anchor.diff:  [,asciidoc]
   ----
   :icons: font
  -:icon-set: pf
  +:icon-set: fas
   ----
   
   You can use font-based icons from any of the following icon sets in your PDF document:
   
  -* *fa* - https://fontawesome.com/v4.7.0/icons (default)
  +* *fa* - https://fontawesome.com/v4.7.0/icons (default, deprecated)
   * *fas* - https://fontawesome.com/icons?d=gallery&s=solid[Font Awesome - Solid^]
   * *fab* - https://fontawesome.com/icons?d=gallery&s=brands[Font Awesome - Brands^]
   * *far* - https://fontawesome.com/icons?d=gallery&s=regular[Font Awesome - Regular^]
   * *fi* - http://zurb.com/playground/foundation-icon-fonts-3[Foundation Icons^]
  -* *pf* - https://paymentfont.com/[Payment font^]
  +* *pf* - Payment font (deprecated)
   
  -The fa icon set is deprecated.
  -Please use one of the other three FontAwesome icon sets.
  +Use of the fa icon set is deprecated.
  +Please use one of the styled FontAwesome icon sets.
  +
  +The pf icon set is no longer maintained.
  +Prefer the brand icons either from fab or fi instead.
   
   Icon-based fonts are handled by the `prawn-icon` gem.
   To find a complete list of available icons, consult the https://github.com/jessedoyle/prawn-icon/tree/master/data/fonts[prawn-icon^] repository.
  
positive.code: 
  Alternatively, you can enable the use of fonts during PDF generation by passing the `icons` attribute to the `asciidoctor-pdf` command instead setting it in the document header.
  
   $ asciidoctor-pdf -a icons=font -a icon-set=pf sample.adoc
  
  By setting `icons`, the xref:theme:admonition.adoc#icon-name[theme can control the icon used for each type of admonition].
  
  
negative.code: [#icon-macro]
  == Insert an icon
  
  Here's an example that shows how to use the Android icon from the Foundation Icons (fi) icon set in a sentence (assuming the `icon-set` is set to `fi`):
  
  [,asciidoc]
  ----
  :icons: font
  :icon-set: fi
  
  Available for icon:social-android[].
  ----
  
  You can use the `set` attribute on the icon macro to override the icon set for a given icon.
  
  [,asciidoc]
  ----
  :icons: font
  
  Available for icon:social-android[set=fi].
  ----
  
  You can also specify the font set using the following shorthand.
  
  [,asciidoc]
  ----
  :icons: font
  
  Available for icon:social-android@fi[].
  ----
  
  It's a good practice to always specify the icon set in some way.
  
  In addition to the sizes supported in the HTML backend (lg, 1x, 2x, etc.), you can enter any relative value in the size attribute (e.g., 1.5em, 150%, etc.).
  
  [,asciidoc]
  ----
  :icons: font
  
  icon:android[set=fab,size=40em]
  ----
  