Designed as a high-tech marketing resource, QR (quick response) codes have many useful applications. These (usually) black-and-white algorithmic codes are gateways to a potential multimedia nirvana.

QR might stand for quit resistance.

QR codes have become ubiquitous short cuts for everything from account log-ins to restaurant menus, but are we at risk of running out of codes?

On the front, Brian Punger’s business card looks like any other. But on the back is a large quick response or QR code that says “Scan me.” People who do just that will upload his contact information ...

Everywhere you look at the South by Southwest conference this week, you see QR codes. The square “quick response” codes turn URLs, vCards, or any kind of text into a jumble of pixels that you can scan ...