Hi positive_charge,
Yes, there is a "Note to Seller" box that can be filled in by your buyers during the Auctiva Checkout process. If you would like to see where this box is located, please click the "Checkout Settings" link under the "My Account" tab within your account, click the "View Screen Shots" link near the top of the page, and look at the second screen shot.
Any additional questions or concerns? Please file a support request using the appropriate link on our help page:
http://www.auctiva.com/free-auction-software-help/help.aspx-Mike