StructuredDocumentTagRangeStart.placeholder property. Gets the [BuildingBlock](../../../aspose.words.buildingblocks/buildingblock/) containing placeholder text which should be displayed when this structured document tag run contents are empty, the associated mapped Xml element is empty as specified via the [StructuredDocumentTagRangeStart.Xml_mapping](../Xml_mapping/) element or the [StructuredDocumentTagRangeStart.is_showing_placeholder_text](../is_showing_placeholder_text/) element is ``True``....empty, the associated mapped XML element is empty as specified...via the StructuredDocumentTa.xml_mapping element or the StructuredDocumentTa...