A coupling (or a coupler) is a mechanism for connecting rolling stock in a train. The design of the coupler is standard, and is almost as important as the track gauge, since flexibility and convenience are maximised if all rolling stock can be coupled together.
Twenty20 cricket, sometimes written Twenty-20, and often abbreviated to T20, is a short form of cricket. It was originally introduced by the England and Wales Cricket Board (ECB) in 2003 for professional inter-county competition in England and Wales. In a Twenty20 game the two teams have a single innings each, which is restricted to a maximum of 20 overs. Together with first-class and List A cricket, Twenty20 is one of the three forms of major cricket recognised by the International Cricket Council (ICC).