Question on Invoice

Hi,

I'm considering buying a vps for my department at college, and Linode seems to be the best choice. Now my boss want to have the receipt/invoice specifically say that the node is, bought by me for the university, so I can get the funding.

I've read previous posts that a printable invoice can be emailed. Then, would it be possible to make a note on the invoice about the purpose of this purchase? or another legitimate way.

Thanks

Alex