EntityReference nodes may be used to represent an entity
* reference in the tree. Note that character references and references to
* predefined entities are considered to be expanded by the HTML or XML
* processor so that characters are represented by their Unicode equivalent
* rather than by an entity reference. Moreover, the XML processor may
* completely expand references to entities while building the
* Document, instead of providing EntityReference
* nodes. If it does provide such nodes, then for an
* EntityReference node that represents a reference to a known
* entity an Entity exists, and the subtree of the
* EntityReference node is a copy of the Entity
* node subtree. However, the latter may not be true when an entity contains
* an unbound namespace prefix. In such a case, because the namespace prefix
* resolution depends on where the entity reference is, the descendants of
* the EntityReference node may be bound to different namespace
* URIs. When an EntityReference node represents a reference to
* an unknown entity, the node has no children and its replacement value,
* when used by Attr.value for example, is empty.
* As for Entity nodes, EntityReference nodes and
* all their descendants are readonly.
*
Note: EntityReference nodes may cause element
* content and attribute value normalization problems when, such as in XML
* 1.0 and XML Schema, the normalization is performed after entity reference
* are expanded.
*
See also the Document Object Model (DOM) Level 3 Core Specification. */ public interface EntityReference extends Node { }