I have had very good luck with the linked pinnies. The numbers even help if you staff does not know who some on might be. They have held up over a year now.

http://www.amazon.com/gp/product/B0015QFQ66?&psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00

How does the sight determine when to change students from freshmen to sophomore. The ability to set a date for when this happens each year would be helpful for reporting when looking at retention numbers of students involved in Intramurals.