XML Companion, The, Third Edition

Alternatives to entities

XML inherited all of the entity-related features described above from the older SGML standard. In part, the entity concept was retained simply for backward compatibility with this standard, and was already considered by many to be an overly engineered approach to solving some of the problems introduced above. In particular, the separation of the declaration from the reference is often considered to be difficult to manage. Recently, alternative approaches have emerged to solve many of the issues handled by entities and discussed above.

Character referencing

As more operating systems and software applications become Unicode-sensitive, the need for entities to represent unusual characters will finally begin to diminish (see ...