Disable HTML Form Input Autocomplete and Autofill

1. Add autocomplete="off" onto <form> element;
2. Add hidden <input> with autocomplete="false" as a first children element of the form.

<form autocomplete="off" method="post" action="">
    <input autocomplete="false" name="hidden" type="text" style="display:none;">
    ...

This formation is going to prevent Chrome and Firefox to offer autofill and autocomplete for all input fields inside the form.