title: CodeIgniter Validation Rules for Email and Password
body: <p>I was used to coding application with CodeIgniter and I'm a total newbie. I just started to learn CodeIgniter 3.0, and and reached to validation rules.</p>
  
  <p>I notice that <code>xss_clean</code> is now gone from the validation class, so what rules should I use in the validation of email and password? Using just <code>trim</code>, <code>valid_email</code>, and required is enough for security?</p>
  
  <p>Sorry if that question has been asked, but I searched around and I see old topics where people is using <code>xss_clean</code>.</p>