Annex C: Extensible Markup Language (XML)
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Here we see a document type element dec1aration that has both an external sub set
and an internal sub set DTD. An external sub set DTD is located in aseparate file,
whereas a internal subset DTD is inc1uded in the XML document. The root XML
element is called top and it must be defined in the external DTD sub set dec1ared in
the "root.dtd" file. The internal DTD sub set is dec1aring a single XML element
called bot.
Miscellaneous
An XML comment may appear anywhere in the document, but outside other
markup. Comments are not part of the document's character data. A comment starts
with the string "". An example ofa comment is:
All of an XML document is case sensitive, both markup and text. This is different
from SGML and HTML and it was introduced to allow markup in non-Latin alphabet characters and to avoid the problem with case folding. This means that element
names, entity names and attribute names all are case sensitive. The following elements are different and thus allowed in an XML document:
This is a road element
This is a Road with a capital R
Other XML standards
The base XML standard is associated with a number of supporting standards. The
most relevant standards are shortly described in this c1ause.
A link is an explicit relationship between two or more data objects or portions of
data objects. In addition to the IDREF mechanism in XML documents a link can be
constructed with attributes on XML elements using a combination of the XLink and
XPointer specification. The XML Linking Language and the XML Pointer Language specify constructs to define links between both external and internal objects
of XML documents. XLink is used to create simple unidirectional hyperlinks between objects in separate XML documents as well as more sophisticated links.
Whereas XPointer is used for addressing internal structures within XML documents,
such as references to elements, character strings and other parts of XML documents.
The Namespace in XML specification (XML99 1999) provide a simple method
for qualifying element and attribute names used in XML documents by associating
them with a namespace identified by a UR! reference. An XML namespace is a collection of names, identified by a URI reference, which are used in XML documents
as element types and attribute names. XML documents can then mix XML elements
297
] >
Here we see a document type element dec1aration that has both an external sub set
and an internal sub set DTD. An external sub set DTD is located in aseparate file,
whereas a internal subset DTD is inc1uded in the XML document. The root XML
element is called top and it must be defined in the external DTD sub set dec1ared in
the "root.dtd" file. The internal DTD sub set is dec1aring a single XML element
called bot.
Miscellaneous
An XML comment may appear anywhere in the document, but outside other
markup. Comments are not part of the document's character data. A comment starts
with the string "". An example ofa comment is:
All of an XML document is case sensitive, both markup and text. This is different
from SGML and HTML and it was introduced to allow markup in non-Latin alphabet characters and to avoid the problem with case folding. This means that element
names, entity names and attribute names all are case sensitive. The following elements are different and thus allowed in an XML document:
Other XML standards
The base XML standard is associated with a number of supporting standards. The
most relevant standards are shortly described in this c1ause.
A link is an explicit relationship between two or more data objects or portions of
data objects. In addition to the IDREF mechanism in XML documents a link can be
constructed with attributes on XML elements using a combination of the XLink and
XPointer specification. The XML Linking Language and the XML Pointer Language specify constructs to define links between both external and internal objects
of XML documents. XLink is used to create simple unidirectional hyperlinks between objects in separate XML documents as well as more sophisticated links.
Whereas XPointer is used for addressing internal structures within XML documents,
such as references to elements, character strings and other parts of XML documents.
The Namespace in XML specification (XML99 1999) provide a simple method
for qualifying element and attribute names used in XML documents by associating
them with a namespace identified by a UR! reference. An XML namespace is a collection of names, identified by a URI reference, which are used in XML documents
as element types and attribute names. XML documents can then mix XML elements