Two tags are only supported by Internet Explorer.
<bgsound />
This tag will set a sound file to play in the background as the Web page is
displayed.
<marquee></marquee>
With the <marquee></marquee> tag, you can create a scrolling text marquee on your Web page.
This tag is also supported by MSNTV.
Netscape only tags
Internet Explorer only tags
MSNTV only tags
XHTML 1.0 tags that aren't supported in any browser
