The only place a patient can be dragged from is the Previous Query view. The namespace for the schema that defines the Patient set XML content is http://www.i2b2.org/xsd/hive/pdo/1.1/
The plugin_drag_drop XML message for a patient is as follows:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<plugin_drag_drop xmlns:ns4="http://www.i2b2.org/xsd/cell/crc/psm/1.1/" xmlns:ns7="http://www.i2b2.org/xsd/cell/crc/psm/querydefinition/1.1/" xmlns:ns3="http://www.i2b2.org/xsd/cell/crc/pdo/1.1/" xmlns:ns5="http://www.i2b2.org/xsd/hive/plugin/" xmlns:ns2="http://www.i2b2.org/xsd/hive/pdo/1.1/" xmlns:ns6="http://www.i2b2.org/xsd/hive/msg/1.1/">
<patient_set patient_set_name="

Pulmonary Funct@09:22:00 [10-06-2008 ] [demo]

" patient_set_id="122">
<patient>
<patient_id>1000000002</patient_id>
</patient>
</patient_set>
</plugin_drag_drop>