The ParentNode.firstElementChild read-only property returns the object's first child Element, or null if there are no child elements.
The ParentNode.lastElementChild read-only property returns the object's last child Element or null if there are no child elements.
The Range.commonAncestorContainer read-only property returns the deepest — or furthest down the document tree — Node that contains both boundary points of the range. This means that if Range.startContainer and Range.endContainer both refer to the same node, this node is the commonAncestorContainer.
The Range.endContainer read-only property returns the Node within which the Range ends. To change the end position of a node, use the Range.setEnd() method or a similar one.
The Range.endOffset read-only property returns a number representing where in the Range.endContainer the Range ends.
The Range.startContainer read-only property returns the Node within which the Range starts. To change the start position of a node, use one of the Range.setStart() methods.
The Range.startOffset read-only property returns a number representing where in the startContainer the Range starts.
The StyleSheet.disabled property indicates whether the style sheet is prevented from applying to the document. A style sheet may be disabled by manually setting this property to true or if it's an inactive alternative style sheet. Note that disabled == false does not guarantee the style sheet is applied (it could be removed from the document, for instance).
media specifies the intended destination medium for style information.
The Text.wholeText read-only property returns all text of all Text nodes logically adjacent to the node. The text is concatenated in document order.  This allows to specify any text node and obtain all adjacent text as a single string.
The TreeWalker.currentNode property represents the Node on which the TreeWalker is currently pointing at.
The TreeWalker.filter read-only property returns a NodeFilter that is the filtering object associated with the TreeWalker.
The TreeWalker.root read-only property returns the node that is the root of what the TreeWalker traverses.
The TreeWalker.whatToShow read-only property returns an unsigned long being a bitmask made of constants describing the types of Node that must to be presented. Non-matching nodes are skipped, but their children may be included, if relevant. The possible values are:
The read-only property ValidityState.tooLong indicates if the value of an <input> or <textarea>, after having been edited by the user, exceeds the maximum code-unit length established by the element's maxlength attribute.