Image without caption

I read that in XHTML, one has to put alt-attributes to images to get a valid img-tags. But then I saw a small rectangular area as I moved my mouse over the image. Can I make an image tag which passes validatio开发者_Go百科n but it won't show that rectangle as I move mouse over the image?

Use a blank alt (IE) and do not specify the title attribute (other browsers):

<img src="myimage.png" alt="" />

The spec says you need to include the alt attribute; however it may be blank as long as you put it there.