I think we'll just copy Drupal here with the following statement:

"All Ubercart documentation pages are © copyright 2007-2008 by the individual contributors and can be used in accordance with the Creative Commons License, Attribution-ShareAlike2.0. This copyleft license (very similar to the GPL) allows anyone to copy, modify, and redistribute modifications of all or part of the Drupal handbook as long as

• the license is included with all copies or redistributions.
• the Ubercart documentation is attributed as the originating document.

These conditions can be waived only if permission is obtained from the copyright holder(s). By posting comments on documentation in the forums or additional pages directly into the Ubercart documentation, Ubercart site members agree that the comments can be revised and/or incorporated wholesale into the Ubercart documentation pages under the licensing terms given above."

I'll get this into the site somewhere. Thanks for asking.