Have you seen QR (Quick Response) Codes?
These are some of the codes posted in the Library to help you get service at a printer, ask a reference question when the Reference Desk or the Library is closed, find citation style guides online quickly, among others.
You need a smart phone or tablet computer with a camera, and an app for reading the codes. Several apps are available for downloading.
Open the app, point your camera at the code, and you’ll be sent to a web page or phone number. Voilà!