Caption Element (XMLA)
For HierarchyInfo elements, the Caption element contains the name of the property that provides the member captions of the hierarchy. The value is equivalent to the MEMBER_CAPTION property defined for axis rowsets in the OLE DB for OLAP specification.
For Member elements, the Caption element contains the caption of the parent Member element in the language specified for the XML for Analysis (XMLA) session. If no caption is available, this element contains the unique name of the member.