Guides.

• QR codes for restaurantsMenu, Wi-Fi and review cards for every table.
• QR codes for teachersSign-ins, quizzes and class links students open in a second.
• QR codes for weddings and eventsRSVPs, directions and a shared photo album.
• Do QR codes expire?Static vs dynamic codes, and how to avoid ones that stop working.
• QR code not scanning?Nine common causes and how to fix each one.