The x-ms-acceleratorKey attribute provides a way to declare that an accelerator key has been assigned to an element.
The x-ms-acceleratorKey attribute enables you to notify screen readers and other assistive technologies that an accelerator key exists. This attribute doesn't provide the accelerator key behavior. You must provide keyboard event handlers, such as onkeypress, onkeydown, or onkeyup, to process accelerator keys in your document.
In contrast to accessKey, which defines Alt+key shortcuts to UI elements in your interface, this attribute assigns keyboard shortcuts for commands you might not have UI for. Accelerator keys consist of the Ctrl key and a letter key.