The Node.lookupPrefix() method returns a DOMString containing the prefix for a given namespace URI, if present, and null if not. When multiple prefixes are possible, the result is implementation-dependent.
The Node.normalize() method puts the specified node and all of its sub-tree into a "normalized" form. In a normalized sub-tree, no text nodes in the sub-tree are empty and there are no adjacent text nodes.
The Node.removeChild() method removes a child node from the DOM. Returns removed node.
The Node.replaceChild() method replaces one child node of the specified node with another.
The Node.setUserData() method allows a user to attach (or remove) data to an element, without needing to modify the DOM. Note that such data will not be preserved when imported via Node.importNode, as with Node.cloneNode() and Node.renameNode() operations (though Node.adoptNode does preserve the information), and equality tests in Node.isEqualNode() do not consider user data in making the assessment.
The ParentNode.append method inserts a set of Node objects or DOMString objects after the last child of the ParentNode. DOMString objects are inserted as equivalent Text nodes.
The ParentNode.prepend method inserts a set of Node objects or DOMString objects before the first child of the ParentNode. DOMString objects are inserted as equivalent Text nodes.
The Node.baseURIObject property returns the nsIURI representing the node's (typically a document or an element) base URL. It's similar to Node.baseURI, except it returns an nsIURI instead of a string.
The Node.isSupported()returns a Boolean flag containing the result of a test whether the DOM implementation implements a specific feature and this feature is supported by the specific node.