Since the exact boundaries of the spans are hard to define even for human annotators (Wiebe et al., 2005a;Yang and Cardie, 2013), the target span in MPQA 2.0 could be a single word, an NP or VP, or a text span covering more than one constituent.
in MPQA 3.0, each target is anchored to the head of an NP or VP, which is a single word.