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As of HTML 5, the auto complete is a form / input Attribute suported by all major browsers.
<form name="form1" id="form1" method="post" autocomplete="off" action="#">
Also, see here some more information about its usage:
If you are preparing an web application or any other Smartphone friendly web page, you might be interested in knowing how to: Disable Autocomplete, Autocapitalize, and Autocorrect.
<input autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false" />
<textarea autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"></textarea>