I have reveiwed the GISB standards (with Theresa Hess) and the data elements for the posting of imbalance information associated with netting and trading has a manditory posting requirement which includes the shipper and, if applicable, the shipper's agent for all imbalances.  Therefore, we have not included in NNG's filing a modification to allow for a "trading fee".  If you have any questions or concerns, please let me know.  Thanks MW