Two-sided table cards that indicate whether diners want others to sit at their table have been introduced in the Hokie Grill on the campus of Virginia Tech University, reports the Collegiate Times. The cards, red with a frowning face on one side and green with a smiling face on the other, were the idea of a student and were deployed by VA Tech Dining at Hokie Grill to test their appeal and effectiveness. If they prove popular, the program may be expanded to other campus dining locations as well.