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