The HTMLInputElement.multiple property indicates if an input can have more than one value. Firefox currently only supports multiple for <input type="file">.
The HTMLTableElement.rows read-only property returns a live HTMLCollection of all the rows in the table. The rows included in the associated <thead>, <tfoot> and <tbody> elements.
The IDBEnvironment interface of the IndexedDB API contains the indexedDB property, which provides access to IndexedDB functionality. It is the top level IndexedDB interface implemented by the window and Worker objects.
The MouseEvent.clientY read-only property returns the vertical coordinate within the application's client area at which the event occurred (as opposed to the coordinates within the page). For example, clicking in the top-left corner of the client area will always result in a mouse event with a clientY value of 0, regardless of whether the page is scrolled vertically.