Plug-ins developed for i2b2 must send XML formatted strings as drag / drop messages between plug-ins. The XML content stored by the workplace consists of any XML contents inside of a <plugin_drag_drop> tag. The namespace for the schema that defines the plugin_drag_drop XML is http://www.i2b2.org/xsd/hive/plugin/
<!-- any xml content -->
The various XML content message formats and their drag source are described throughout the specification.