Developers found that they hide iTunes gift cards
When you buy an iTunes gift card and then decide to "pay" it off in the App Store, the camera on the iPhone, iPad or Mac can scan the code so you do not waste time typing. The mechanism is designed so cleverly that Apple uses the hidden font, and in addition to the text, the frames around the code are recognized.
To this conclusion came the developers from the company Equinux, who tried to recognize the camera codes with a different font and borders, but their attempts to no avail. The specialists found that the font itself is hidden deep in iTunes, but there was no information about it in the CodeRedeemer plugin. Two fonts – Scancardium and Spencardium, the developers found in the framework CoreRecognition.framework. The first is used to enter and recognize codes, and the second – to hide credit card data.
Fonts can be installed on the same Mac in just a couple of clicks, and then used in different applications. To ordinary users, in general, such information is unlikely to be useful, but developers can create their own cards with promotional codes of the App Store, so that users recognize them in a standard application.
Usually iTunes gift cards are used to replenish the Apple ID cash account. With their help, you can buy applications, movies, pay subscription to Apple Music, buy storage in iCloud and so on.