Your iPhone screen is hiding a secret QR code.

A new report from The Information this week highlighted that Apple has hidden two small QR codes in the iPhone screen’s glass.

If you haven’t noticed them before don’t worry, when we said they were small we meant really small. One of the QR codes is reportedly the size of a grain of sad and can only be seen on the phone using special equipment. The other is a bit larger, roughly the size of the tip of a crayon, and is printed on the reverse side of the glass along the device’s blank border,

Both of the QR codes are placed on the glass by Apple during the manufacturing process as a way to track the glass as it moves through the manufacturing process and to reduce defects.

Your iPhone’s display isn’t the only thing on the phone with a QR code. Apple adds QR codes to a number of the internal components within the phone as a way to keep track of their origin.

The glass display on the iPhone has reportedly been getting QR codes since 2020 as a way to keep track of how many displays are being made as well as how many defective units might be thrown away during the manufacturing process.

The QR codes have been present on phones since the iPhone 12, where the code is located directly above the front speaker, and they’re having a positive effect on the manufacturing process.

Before the implementation of the QR codes, The Information notes that Apple was discarding 3 out of every 10 displays that were made, resulting in a loss of hundreds of millions of dollars each year. While there’s still some loss, the program has helped drop that number to 1 in 10 displays, helping to cut down considerably on the loss.