Before revision:  However, such problem setup has two inherent limitations that (1) it can only extract a flat list of information and (2) it assumes that the input data is serialized, often by a simple rule-based script.
After revision:  However, such problem setup has two inherent limitations that (1) it cannot easily handle complex spatial relationships and (2) it assumes that the input data is serialized, often by a simple rule-based script.