The onvrdisplaydisconnected event handler property of the Window interface is called when a compatible VR device has been disconnected from the computer (when the vrdisplaydisconnected event fires).
The onvrdisplaypresentchange property of the SpeechSynthesis interface represents an event handler that will run when the presenting state of a VR device changes — i.e. goes from presenting to not presenting, or vice versa (when the onvrdisplaypresentchange event fires).
The Window.onunhandledrejection property is an event handler for processing unhandledrejection events, which are raised for unhandled Promise rejections.
The DeviceLightEvent provides web developers with information from photo sensors or similiar detectors about ambient light levels near the device. For example this may be useful to adjust the screen's brightness based on the current ambient light level in order to save energy or provide better readability.
ongotpointercapture is an EventHandler property of the Element interface that returns the event handler (function) for the gotpointercapture event type.
The KeyboardEvent.code property represents a physical key on the keyboard (as opposed to the character generated by pressing the key). In other words, this property returns a value which isn't altered by keyboard layout or the state of the modifier keys.
The MouseEvent.ctrlKey read-only property returns a Boolean that indicates if the control key was pressed (true) or not (false) when the event occured.
The MouseEvent.getModifierState() method returns the current state of the specified modifier key: true if the modifier is active (i.e., the modifier key is pressed or locked), otherwise, false.
The MouseEvent.region read-only property returns the id of the canvas hit region affected by the event. If no hit region is affected, null is returned.