code: function link(href, title, text) {
  
    var reLabelFirst = /^(.*?)\s*\?([^?\s]*)\?(\*?)(X?)(H?)$/;
    var reLabelAfter = /^\?([^?\s]*)\?(\*?)(X?)(H?)\s*(.*)$/;
  
    var m = text.match(reLabelFirst);
    if (m) return renderInput(m[1], m[2], m[3], m[4], m[5], href, title, true);
  
    m = text.match(reLabelAfter);
    if (m) return renderInput(m[5], m[1], m[2], m[3], m[4], href, title, false);
  
    return fallback.link.call(this, href, title, text);
  }
docs: markdown link syntax extension for forms