It is generally accepted that when the iPhone 12 launches there will be four different models including a new smaller version, which will roughly follow the dimensions of the iPhone SE from 2016, but with a borderless display.
To date this was an unsubstantiated rumour, but now evidence has emerged in the iOS 14 beta.
The third developer beta of iOS 14, which arrived on 22 July, expands the Display Zoom feature that is hidden under Display and Brightness in Settings to smaller phones - with the indication that it will be available for 5.8in iPhones thanks to the arrival of a new 5.4in iPhone model. (Read: how to install the iOS beta)
The setting makes the icons and other elements on the screen of an iPhone or iPad a little larger, which should make it easier for far-sighted people to use.
The Display Zoom feature has been around for a while - it arrived with the launch iPhone 6 Plus, which could mimic the screen of the iPhone 6 in Display Zoom mode. But when Apple introduced the 5.8in iPhone X it didn't offer Display Zoom because there wasn't a smaller screen size available to mimic. When the iPhone XS Max and iPhone 11 Pro Max arrived they offered Display Zoom as they could simply show the 5.8in screen as used by the smaller iPhone XS and iPhone 11.
The iPhone 11 and iPhone XR are also able to offer Display Zoom mode because they can display the iPhone Max screen at a lower resolution.
What's apparent from the latest iOS 14 beta is that Apple is adapting iOS to suit a new smaller resolution. A new resolution with the same aspect ratio as the iPhone X display, but smaller.
9to5Mac has been using the iOS Simulator on a Mac to investigate the various resolutions available in the iOS 14 beta - including a resolution of 960 x 2,079 pixels - and writes that they "strongly believe" the interface is destined for the rumoured smaller 5.4in iPhone 12 model.
9to5Mac also highlights that this 5.4in iPhone's display resolution of 960 x 2,079 indicates it will have a higher pixel density than the current iPhones.
To find out all the latest information about the iPhone 12 read our analysis of the iPhone 12 rumours here.