FERC first required transmission owners to provide non-discriminatory access to their lines in Order Nos. 888 and 889, building on the model it had used to require interstate natural gas pipelines to provide access to pipeline capacity. In those orders, FERC noted that ISOs could provide the additional assurance of independence from the owners, and the elimination of multiple ("pancaked") rates to transmit electricity over long distances. Shortly thereafter, FERC Order No. 2000 encouraged the formation of RTO's to regionally manage portions of North America's electricity grid.