How do you disable browser Autocomplete on web form field / input tag?

Question

How do you disable autocomplete in the major browsers for a specific input (or form field)?

Answer 1

Firefox 30 doesn't accept autocomplete="off" for passwords, opting to prompt the user instead of whether the password should be stored on the client.

Note: 

The password manager always prompts if it wants to save the password. Passwords will not be saved without permission from the user.

According to the Mozilla Developer Network, the Boolean form element attribute autocomplete prevents form data from being cached in older browsers.

<input type="text" name="foo" autocomplete="off" />