Hi, I came across a notice that explains icons used for subway stations in Tokyo. Station numbers consist of a letter representing the subway line and a number for the station. They are circled with a color that represents the subway line making it easy to find your station. I think the first sentence should be "A station number consists of a letter representing the subway line and the number for a station." The second sentence might be "The colors circling the icons are unique to each subway line, which makes it easy for you to find your destination." Thanks in advance.