code: function (dropdown, target, settings, position) {
        var sheet = Foundation.stylesheet,
            pip_offset_base = 8;
  
        if (dropdown.hasClass(settings.mega_class)) {
          pip_offset_base = position.left + (target.outerWidth() / 2) - 8;
        } else if (this.small()) {
          pip_offset_base += position.left - 8;
        }
  
        this.rule_idx = sheet.cssRules.length;
  
        //default
        var sel_before = '.f-dropdown.open:before',
            sel_after  = '.f-dropdown.open:after',
            css_before = 'left: ' + pip_offset_base + 'px;',
            css_after  = 'left: ' + (pip_offset_base - 1) + 'px;';
  
        if (position.missRight == true) {
          pip_offset_base = dropdown.outerWidth() - 23;
          sel_before = '.f-dropdown.open:before',
          sel_after  = '.f-dropdown.open:after',
          css_before = 'left: ' + pip_offset_base + 'px;',
          css_after  = 'left: ' + (pip_offset_base - 1) + 'px;';
        }
  
        //just a case where right is fired, but its not missing right
        if (position.triggeredRight == true) {
          sel_before = '.f-dropdown.open:before',
          sel_after  = '.f-dropdown.open:after',
          css_before = 'left:-12px;',
          css_after  = 'left:-14px;';
        }
  
        if (sheet.insertRule) {
          sheet.insertRule([sel_before, '{', css_before, '}'].join(' '), this.rule_idx);
          sheet.insertRule([sel_after, '{', css_after, '}'].join(' '), this.rule_idx + 1);
        } else {
          sheet.addRule(sel_before, css_before, this.rule_idx);
          sheet.addRule(sel_after, css_after, this.rule_idx + 1);
        }
      }
docs: Insert rule to style psuedo elements