11:49:20 AM Oct 28th 2013
The ID code may not necessarily just include numbers. If the ID is an alphanumeric pattern (including letters A-Z and digits 0-9), then there is the possibility of having up to 60,466,176 unique ID codes. Also, in many colleges, former students' ID numbers are retired after a certain period, allowing the number to be reused. If the military in this world does the same (even for just deceased former soldiers), then there is no problem with Claude's ID.