The View Item request can use a property and value to uniquely identify a document:
<property>name</property><value>val</value>The name argument must be the name of a metadata property that is both stored and indexed (see the Structured Content Specification section 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.

