This initial Xpointer concept is based upon preliminary research of the Xpointer tutorial at http://www.zvon.org/xxl/xpointer/tutorial/OutputExamples/xpointer_tut.html

If for example a surveyor conducted a cave survey and wanted to equate (or link) one of the stations in the new survey data file with a station contained in a different survey data file, the new survey could have a tag-pair that contains a statement similar to this:

<EquivalentStation>
<link xmlns:xlink="http://www.w3.org/2000/xlink" xlink:type="simple"
xlink:href="Fulford.xml# xpointer(//CaveSurvey/Survey/Shot/From/StationName,'A13')">
</link>
</EquivalentStation>

In this example, business is conducted largely in the second line. The statement points to station "A13" in a survey data file named Fulford.xml. (This statement is built upon the XML syntax specified in version 0.4 of Cave Surey Data in XML.)

This is a simple beginning to meeting some of the requirements levied for cross linking files to build cave systems or equating a station in one survey to another. Added work will inprove the capability over time. DSK, 17 January, 2000