It's a workaround for buggy IE where there is no cursor "hand" like other browsers. So it does the pointer cursor and ignores the second. Meanwhile other browsers do the second. I suspect you found it or don't like it because validation throws an error.
You seriously need to stop wasting your time with validation. Instead of getting creative work done you are spending valuable hours on syntax stuff that will work for decades in all browsers.
Throw off the shackles of validation.
