If you’ve been an iPhone user for a while, you may’ve noticed that Apple ended the iPhone ’S’ naming scheme that had been used for over a decade. And the reason has to do with the iPhone’s new update cycle.

Previously, Apple released a major update to iPhone every two years, with a minor update inbetween. Like the 3G featuring a completely new design, and the 3GS featuring a speed bump and lower price. Or the 4 having a radical new design, and the 4S simply including a new software feature called Siri.

The S naming scheme worked well back then, but things got a little messy after the 6S was released.