Campus mail (Interoffice mail) addresses should contain the person's name, department, building and room number:

EMPLOYEE NAME
DEPARTMENT
BUILDING + ROOM NUMBER

All undergraduate student's campus mail should be addressed by the name and box number located in the Frist Campus Center (XXXX = Student mailbox number):

STUDENT NAME
XXXX Frist Campus Center
Princeton, NJ 08544

You can search for student mailbox number here.

Any campus accountable mail should also include a return address in case of non-collection