The property element is a child of viewInContext. It has no child elements.
This element represents a method of retrieving an indexed item’s source when performing a viewInContext request (see the docContextID element for another method). The request can use a property and value to uniquely identify a document, as shown:
<property>name</property><value>val</value>The name argument must be the name of a metadata property that is both stored and indexed (see Appendix B, Structured Content Specification for the atg:index option). The val argument is the value of that metadata property to test with. Typically, this mode is used with ID-type metadata properties which uniquely identify each item.

