Sadly the other posters are correct that you're
...actually as corrected by kRON, you are ok with your IE7 and a strict doc, but most of us with IE6 requirements are reduced to JS or class references for this, but it is a CSS2 property, just one without sufficient support from IE^h^h browsers.
Out of completeness, the type selector is - similar to xpath - of the form [attribute=value]
but many interesting variants exist. It will be quite powerful when it's available, good thing to keep in your head for IE8.