1. I agree with Steph on using an external service and a link. If that is not possible, then do not install the dll into the GAC as it will cause future headaches in the future for sure. Instead, just reference the dll through a simple path file.

2. Fully test the QR Code by scanning them though a real scanner device not just a software one if your reports containing any barcode will be printed and read by real scanners out there. Barcoding seems to be simple (and it is) if it's performed correctly which means you use a good barcode encoder (we can help on this), you test it with a real device AND you get it verified by using a verifier device.

3. By the way, the link to the QR Code spec file is illegal. Look, QR Code is public BUT you have to pay for a license to ISO organization! That pdf file has this watermark at every page

"Licensed to SCANBUY, INC./ASHISH MUNI

ISO Store order #:762844/Downloaded:2006-08-01

Single user licence only, copying and networking prohibited"

The last phrase is far than clear