XML in a Nutshell, 3rd Edition

Child Sequences

Another very common form of XPointer is one that descends exclusively along the child axis, selecting elements by their positions relative to their siblings. For example, xpointer(/child::*[position( ) = 1]/child::*[ position( ) = 2]/child::*[position( ) = 3]) selects the third child element of the second child element of the root element of the document. The element( ) scheme allows you to abbreviate this syntax by providing only the numbers of the child elements separated by forward slashes. This is called a child sequence . For example, the previous XPointer could be rewritten using the element scheme in the much more compact form element(/1/2/3).

For example, the aforementioned Motivation and Summary section of the “Namespaces in XML” recommendation at http://www.w3.org/TR/1999/REC-xml-names-19990114/xml-names.xml is given as a div element. It so happens that this div element is the first child element of the second child element of the root element. Therefore, http://www.w3.org/TR/1999/REC-xml-names-19990114/xml-names.xml#element(/1/2/1) points to this section.