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.
The CueCat, styled :CueCat with a leading colon, is a cat-shaped handheld barcode reader that was released in 2000 by the now-defunct Digital Convergence Corporation. The CueCat enabled a user to open a link to an Internet URL by scanning a barcode — called a "cue" by Digital Convergence — appearing in an article or catalog or on some other printed matter. In this way, a user could be directed to a web page containing related information without having to enter a URL. The company asserted that the abi..