Current rights expression languages (RELs) only allow for rights holders to dictate terms to the end users. This limits their use as a means for negotiating electronic contracts and end users are not able to request changes in their rights contracts. In this paper we propose extensions to ODRL that allow end users to request changes and for the rights holder to grant or deny these changes. These extensions allow the end user to request changes to their current rights, and for the rights holder to grant or refuse the request. We also provide two examples to demonstrate possible uses of our extensions. The extensions we discuss can also be implemented in other RELs like XrML
