-moz-force-broken-image-icon is an extended CSS property. The value 1 forces a broken image icon even if the image has an alt attribute. When the value 0 is used the image will act as usual and only display the alt attribute.
This value for CSSbackground-image lets you use a portion of a larger image as a background. This allows you to, for example, use different parts of one larger image as backgrounds in different parts of your content.
A DOMCursor object represents an ongoing operation over a list of results. It is an enhanced DOMRequest that allows to iterate through a list of results asynchronously. Each time its continue() method is called, the DOMCursor tries to reach the next result in the list and calls its result's success or error accordingly.
A DOMRequest object represents an ongoing operation. It provides callbacks that are called when the operation completes, as well as a reference to the operation's result. A DOM method that initiates an ongoing operation may return a DOMRequest object that you can use to monitor the progress of that operation.
The Element.scrollIntoViewIfNeeded() method scrolls the current element into the visible area of the browser window if it's not already within the visible area of the browser window. If the element is already within the visible area of the browser window, then no scrolling takes place. This method is a proprietary variation of the standard Element.scrollIntoView() method.