XmlHelp
From canSAS
Help for XML
- XML
 - EXtensible Markup Language 
http://www.w3schools.com/xml/
http://www.w3.org/XML/
http://en.wikipedia.org/wiki/XML
http://www.zvon.org/xxl/XPathTutorial/General/examples.html - XSL (or XSLT)
 - EXtensible Stylesheet Language 
http://www.w3schools.com/xsl/
http://www.w3.org/Style/XSL/
http://en.wikipedia.org/wiki/Extensible_Stylesheet_Language
http://en.wikipedia.org/wiki/XSLT - XPath
 - XPath is a language for finding information in an XML document. 
http://www.w3schools.com/xpath/
http://www.w3.org/Style/XSL/
http://en.wikipedia.org/wiki/XPath - Schema
 - An XML Schema describes the structure of an XML document. 
http://www.w3schools.com/schema/
http://www.w3.org/XML/Schema
http://en.wikipedia.org/wiki/XSD - XML Namespaces
 - XML namespaces are used for providing uniquely named elements and attributes in an XML instance. 
http://www.zvon.org/xxl/NamespaceTutorial/Output
http://en.wikipedia.org/wiki/XML_namespaces
http://www.w3schools.com/XML/xml_namespaces.asp - XML Foreign Elements
 - Inclusion of elements, at select locations, that are not defined by the cansas1d.xsd XML Schema 
http://books.xmlschemata.org/relaxng/relax-CHP-11-SECT-4.html
http://www.w3.org/TR/SVG/extend.html
http://www.google.com/search?q=XML+foreign+elements