A network-based solution for processing unknown or unexpected property encountered during a migration or archiving operation may include, as embodied in various systems, methods, and non-transitory computer-readable storage media, accessing a plurality of objects stored in memory of a source computing system. The solution may include performing a discovery assessment on each of a plurality of operator-selected objects. The discovery assessment may include examining a property associated with a document of each selected object and notifying the operator when the examination determines that the property is unknown or unexpected.