I would presume that the receipt of a 1098-T prompted the OP to file an amendment to claim either an education credit or a tuition/fees deduction. This would generate an additional refund, but if the form 8863 did not accompany the 1040X, for example, the IRS would send a letter requesting that form. The form 8863 would be required to claim an education credit. People sometimes forget to file the supporting forms with the 1040X. I am guessing that this is the additional "document" they have requested, as this is the most likely scenario. Failing to respond will do nothing more than prevent the additional refund from being issued.
In any case, each year stands alone and 2010 expenses cannot be applied to a 2011 return.