What tag do you use if you want text to pop up when the browser hovers his/her mouse over a graphic on your page in Internet Explorer?

The alt attribute in an img tag provides alternative text that displays when an image cannot be loaded. While the question asks about hover behavior in Internet Explorer specifically, the alt attribute was historically the closest mechanism for providing descriptive text about graphics (though the title attribute is the correct one for tooltips). The ctrl, hover, and over options are not standard HTML attributes.