The NamedNodeMap interface is defined in the W3C Document Object Model (DOM) Level 2 Core Specification. (Refer to http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113.)

Objects implementing the NamedNodeMap interface are used to represent collections of nodes that can be accessed by name. Note that NamedNodeMap does not inherit from NodeList; NamedNodeMaps are not maintained in any particular order. Objects contained in an object implementing NamedNodeMap may also be accessed by an ordinal index, but this is simply to allow convenient enumeration of the contents of a NamedNodeMap, and does not imply that the DOM specifies an order to these Nodes.

NamedNodeMap objects in the DOM are live.