Document type definition. An optional part of the XML document prolog, as specified by the XML standard. The DTD specifies

constraints on the valid tags and tag sequences that can be in the document. The DTD has a number of shortcomings, however,

and this has led to various schema proposals. For example, the DTD entry says that the XML

element called username contains parsed character data-that is, text alone, with no other structural elements under it. The

DTD includes both the local subset, defined in the current file, and the external subset, which consists of the definitions

contained in external DTD files that are referenced in the local subset using a parameter entity.

The very first thing in an XML document, which declares it as XML. The minimal declaration is . The

declaration is part of the document prolog.

A transaction whose boundaries are defined by an EJB container. An entity bean must use container-managed transactions.What is content

In an XML document, the part that occurs after the prolog, including the root element and everything it contains.