code: function checkLegacy(conf) {
    var out = [];
  
    if (conf.auth) {
      logger.error('`auth` is deprecated, please use `users` instead.');
    }
  
    if (conf.userScript) {
      out.push(''
        + '`userScript` is deprecated, please place '
        + '`user.js` in `~/.tty.js/static/user.js` instead.');
    }
  
    if (conf.userStylesheet) {
      out.push(''
        + '`userStylesheet` is deprecated, please '
        + 'place `user.js` in `~/.tty.js/static/user.js` instead.');
    }
  
    if (conf.stylesheet) {
      out.push(''
        + '`stylesheet` is deprecated, please place '
        + '`user.css` in `~/.tty.js/static/user.css` instead.');
    }
  
    if (conf.hooks) {
      out.push(''
        + '`hooks` is deprecated, please programmatically '
        + 'hook into your tty.js server instead.');
    }
  
    if (out.length) {
      out.forEach(function(out) {
        logger.error(out);
      });
      logger.error('Exiting.');
      process.exit(1);
    }
  }
docs: Check Legacy