I have observed that firefox does not prompt to remember password for yahoo mail. Then after searching for it over net, I found that we can restrict browsers from prompting to remember passwords. In HTML <form> elelement, we can use autocomplete=”off” to restrict browsers from prompting. Yahoo mail uses form element like this <form method=“post” action=“https://login.yahoo.com/config/login?” autocomplete=“off” name=“login_form”>.
In this webpage, I have found a bookmarklet which will remove autocomplete=”off” parameter in form element. So, when we click login, browser submits the login/password to server and prompts the password remember dialog [because, now form element does not have autocomplete="off" parameter]. Once the browser remembers password info, from next time on, it does not check for autocomplete parameter in form element.
How to execute: open firefox and enter mail.yahoo.com. Once the page is loaded, copy the bookmarklet and paste it in the address bar and execute. It says it has removed autocomplete parameter from the form. Then, enter your login/password info and press enter. Then, firefox “remember password dialog” appears.
You can copy the bookmarklet from the above mentioned webpage or I have copy/pasted the same bookmarklet here.