Font-Awesome/scss/_icons.scss

// Font Awesome uses the Unicode Private Use Area (PUA) to ensure screen
// readers do not read off random characters that represent icons


//loop through all icons
@each $var in $fa-vars {
  //create icon placeholders
  %fa-#{nth($var, 1)} {
    &:before {
      content: nth($var, 2);
    }
  }
  
  //create icon classes if enabled
  @if $fa-show-classes == true {
    .#{$fa-css-prefix}-#{nth($var, 1)} {
      @extend %fa-#{nth($var, 1)};
    }
  }

}

//lets loop through the alias's
@each $alias in $fa-alias {

  //lets create the placeholder
  %fa-#{nth($alias, 1)} {
    @extend %fa-#{nth($alias, 2)};
  }

  //create icon classes if enabled
  @if $fa-show-classes == true {
    .#{$fa-css-prefix}-#{nth($alias, 1)} {
      @extend %fa-#{nth($alias, 2)};
    }
  }

}