Another potential issue with custom QR codes is scanning them. Often the QR code specification has been pushed so far that only camera based barcode software applications can read them; this includes mobile apps for iPhone and Android. However industrial barcode scanning software and scanners often can not read these custom QR codes; this includes the barcode scanners by Zebra and Leuze. These industrial barcode scanners are not as tolerant to QR Code modifications.
If a project requires the QR Code to be read as a part of manufacturing, often to be correlated with another tag technology such as NFC, it likely can not be a custom QR code but a standard QR code so that industrial barcode scanners can read the barcode.