08 is grade ~4. I don't know. Personal guess may be the title number. For example, we are engineering students. Regarding this 4, you can look at the student numbers of other subjects. In contrast, 303 is the number of our college. This can be seen from the textbook of course selection. All courses offered by the college have the number of the college. 1555 is a personal number. ~ that's all I know.