Interface Builder

If your project contains Interface Builder files (such as storyboards and XIBs), Periphery will take these into account when identifying unused declarations. Periphery parses these files to identify which classes, @IBOutlet properties, @IBAction methods, and @IBInspectable properties are actually referenced. Only those members that are connected in the Interface Builder file will be retained. Any @IB* members that are declared but not connected will be reported as unused.