What do the numbers on Shinkansen cars mean?
Conventional train cars are given model numbers and katakana characters to show the type and role of each car. In case of the Shinkansen, three-digit numbers are given to cars, with the first digit showing which design a car is based on, the second digit referring to the car's purpose, and the third digit showing the car type.
The first-generation Shinkansen―the 0 series―initially did not have a series number. It was designated 0 in 1982 to distinguish it from the Tohoku and Joetsu Shinkansen trains—called the 200 series—when they came into service. The first-generation 0 series was followed by the 100 series, the 300 series and the 700 series.
The 800 series is used for Kyushu Shinkansen trains, while the 900 series is reserved for test cars, maintenance and other non-passenger trains. With no single-digit numbers left for a new series, the letter "N" was added to 700 to create the N700 series name, with N meaning "new" or "next." Later, the N700A series was named by further adding "A"—from the word "advance."