The name of the system is not a criterion for inclusion or exclusion. Some cities use metro as a brand name for a transit line with no component of rapid transit whatsoever. Similarly, there are systems branded light rail that meet every criterion for being a rapid transit system. Some systems also incorporate light metro or light rail lines as part of the larger system under a common name. These are listed, but the light rail lines are not counted in the provided network data. Certain transit networks may match the service standards of metro systems, but reach far out of the city and are sometimes known as S-Bahn , suburban, regional or commuter rail. These are not included in this list. Neither are funicular systems, or people movers , such as amusement park, ski resort and airport transport systems.
Holdouts controlling 7% of the bonds, including some small investors, hedge funds , and vulture funds     led by Paul Singer 's Cayman Islands -based NML Capital Limited , rejected the 2005 and 2010 offers to exchange their defaulted bonds. Singer, who demanded US$832 million for Argentine bonds purchased for US$49 million in the secondary market in 2008,  attempted to seize Argentine government assets abroad  and sued to stop payments from Argentina to the 93% who had accepted the earlier swaps despite the steep discount .  Bondholders who instead accepted the 2005 offer of 30 cents on the dollar, had by 2012 received returns of about 90% according to estimates by Morgan Stanley .  Argentina settled with virtually all holdouts in February 2016 at a cost of US$ billion; NML received US$ billion, a 392% return on the original value of the bonds.