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--- a/Allura/allura/model/artifact.py
+++ b/Allura/allura/model/artifact.py
@@ -505,6 +505,8 @@
         history_class = Snapshot
 
     version = FieldProperty(S.Int, if_missing=0)
+    # Not null if artifact originated from external batch import
+    import_id = FieldProperty(S.ObjectId, if_missing=None)
 
     def commit(self):
         '''Save off a snapshot of the artifact and increment the version #'''