Enter your graduation date in the form. You will then be given the option to choose your Series.
Your Series is not necessarily your platoon number. Each graduation date has a Lead and a Follow Series. Each Series is made up of 3 or 4 platoons.
If the Lead Series number is 3040 it would contain Platoons 3040, 3041 and 3042. In this example, the Follow Series would be 3052 and would contain Platoons 3052, 3053 and 3054.