I am using Moodle 1.9.2+ (Build: 20080917).
ID Number is an advanced optional that it's possible to view in user edit profile form and I prefer set up this field as locked within Manual Accounts, so that the students cannot modify it.
However it would be easier to find it in the user profile form (you can see the image), but I don't know as it is possible to make it.
Any suggestions? Thanks!!