QR Codes - for technical folk

By the end of this post, I hope to pass on a little bit of information about QR codes - just some things I've picked up over time in dealing with them.

This post is targeted at technical folk. For the non-technical version, go here

Where are they from?
Denso Wave, a subsidiary of Toyota, first created them to track motor vehicle parts, and it wasn't too long before someone thought they'd be useful in the wild.

What do they do?
QR codes themselves just encode text, with varying degrees of capacity and redundancy. Often, the text is a link off to a web site, but it can also be plain text or a v-card or something like that. So QR codes are basically just hyperlinks in the physical world, enabling users to go to content quickly and easily.

Where does one get them?
The easiest way to get started is to google "QR Code generator" and go from there.

Do they have to be black and white?
Not at all - there are many ways to play with them - just as long as the contrast is maintained. Many deployments use a small logo or picture in the middle of the code or as part of the design. This is possible because the codes have a certain amount of error correction.
http://designerqrcodes.wordpress.com/designer-qr-code-art-gallery/ has good examples of interestingly crafted codes.

What are the legal requirements?
The term "QR Code" is owned by Denso Wave (a subsidiary of Toyota), and their only requirements are listed here:
http://www.denso-wave.com/qrcode/faqpatent-e.html
The requirements are extremely lenient - basically the codes themselves can just be used, and using the phrase "QR Code" needs a mention of Denso Wave as the owners of the term. Somewhere :)

Any tips?

• Create different codes for each execution of your campaign, so you'll know which codes led users to the target URL.
• Ideal size is 20x20mm, or the "pixels" to be 0.7x0.7mm, whichever is *bigger* (encoding more text will lead to more intricate patterns). Of course, this is for printed media within arm's reach of the user. Billboards and such will need special treatment.
• Make sure the content the user is going to is mobile friendly. Users will almost exclusively use mobile phones to scan the codes, and will probably use the same to actually visit the destination.
• QR codes are not a silver bullet. They're not a call to action in themselves, so don't expect addition of QR codes to printed media to suddenly and drastically increase visits.
• Accept no substitutes. QR codes are the most widely used mobile codes - there are competitors out there, but they don't have the ubiquity of QR Codes - and  the companies peddling proprietary formats often charge to create them.
• Stats and analytics are important - but beware of companies offering "free" analytics. Such operators still make money, potentially by selling details about visitors to your site. Rather go with a company that will charge you for analytics - your data will be safer this way. If you don't want to spend all that money, using Google Analytics on the destination page, combined ith some GET data will give you a fair amount of information. http://www.gloo.co.za?qr=001 and http://www.gloo.co.za?qr=002 are examples of what I'm talking about - they go to the same place, but indicate different entry points.
• When generating codes, it's best to save them as a vector based format (like SVG) - your print people will thank you, because they can be scaled to suit whatever media they're designing for.

For more info, Wikipedia has an article:
http://en.wikipedia.org/wiki/QR_code
QR Codes, explained by commoncraft
http://www.commoncraft.com/video/qr-codes
QR code generator:
http://beqrious.com/generator