lXML is an abbreviated
version of SGML, to make it easier for you to define your own document types, and to
make it easier for programmers to write programs to handle them.
1.It omits the more complex and less-used parts
of SGML
in return for the benefits of being easier to write applications
for, easier to understand, and more suited to delivery and interoperability over the Web.
2.But it is still SGML, and XML files may still
be parsed
and validated the same as any other SGML file.
