The Great Eastern was renowned for operating an intensive suburban service known as the "Jazz" service. The different classes on the trains were indicated by different coloured stripes along the top of the carriage sides. The stripes allowed passengers to find their compartments more quickly at stations and reduced stopping times. They were yellow for first class and blue for second class. In 1920, the GER also introduced a system of colour-coded boards on the side and rear of the guard's van, which would be nearest the gates and concourse at terminus stations and thus allow passengers to identify the service they needed. This colourful combination was regarded, in the parlance of the time, as 'jazzy'.