There are stations in the system (which must all be visited for the Class B record) and multi-station complexes (necessary for the Class C record), on different routes. Challengers cover 662 miles of track in passenger service, while only being able to go to the toilet at 80 of the stations. All of the official record holders, except one, have held the record for 468 stations, since all official records are from before September 2015, when the 7 Subway Extension opened. One record holder has the record for the 469 stations, after the opening of the 7 Subway Extension but before the January 2017 opening of the Second Avenue Subway. there were no record holders for the -station challenge. The Amateur New York Subway Riding Committee mandates that rides must be completed on a single fare. The Guinness record rules allow a rider to exit and re-enter the system during the course of the run, and contestants may walk or take "scheduled public transport" between stations. According to the Guinness rules, "the use of private motor vehicles, taxis or any other form of privately arranged transport (bicycles, skateboards, etc.) is not allowed." Matthew Ahn's attempts, for instance, use the out-of-system transfers allowed under the Guinness rules. The complete Guinness rules can be found on the Rapid Transit Challenge website and are similar to the rules for the London Underground's Tube Challenge. The Amateur New York Subway Riding Committee is not an official body and does not validate any record attempts, nor does the Metropolitan Transportation Authority. On August 23–24, 2006, Donald Badaczewski and Matt Green made a run setting the skip-stop record. During their run, a Class C attempt as defined by the Amateur New York Subway Riding Committee, they were required to pass through, but not necessarily stop at, each station. Thus they utilized express trains where possible to save time. They did this on a single fare, not exiting the system until the completion of the race. They posted a time of 24 hours, 2 minutes, breaking the previous Class C record of 25 hours, 11 minutes for this feat set in 1998 by Salvatore Babones and Mike Falsetta. "Metro" broke the story of this Class C record. An "AM New York" article suggested that the news environment at the time created a perfect opening for such a lighthearted story. Pundits frequently questioned the pair on how they had relieved themselves during their journey. The two invariably answered that they had "held it" or "toughed it out," despite the fact that "it was tough."