The DocBook definition of a book is very loose and general. Given the variety of books authored with DocBook and the number of different conventions for book organization used around the world, any attempt to impose a strict ordering of elements would make the content model extremely complex. DocBook 4 was created when the only XML schema language was the Document Type Definition (DTD) so the official DocBook 4 schemas are all DTDs. But DTDs predate namespaces, so a DTD is not suitable as a namespaceaware schema.
XInclude is a standard for assembling XML instances into another XML document through inclusion. A master file can be dynamically created from smaller XML documents without having to physically duplicate the content of the smaller files.
@LarryRowland Basically, first level elements from assembly. If we should go" deeper" or not is a question to debate. Let's assume you want to build an assembly file which contains lots of different resources, modules, or other components. The XInclude processor can do that because it fully recognizes each XInclude element from its unique namespace attribute. But what about relative graphics file references? An XIncludeaware parser does not automatically know that the fileref attribute in an imagedata element is a path that needs to be resolved relative to the current file's location.
It is the stylesheet's responsibility to do that. Be sure that you associate the DocBook V5. 0 namespace with the corresponding DocBook V5. 0 grammar. Entity definition files are now maintained by W3C. You can reference definition files with entity definitions you are interested in and then reference imported entities. There is an alternative schema for DocBook V5. 0 that contains DocBook V5. 0, a normative RELAX NG Grammar for DocBook V5.
0. W3C XML Schemas There is no XML Schema for any language in this namespace at this time. It is also possible to construct documents from different files using XInclude. Recasting the previous example using XInclude yields: but we must declare the XInclude namespace.
The DocBook definition of a book is very loose and general. Given the variety of books authored with DocBook and the number of different conventions for book