In modeling the effects of the Person-Case Constraint (PCC), a common claim is that 3rd person "is not a person". However, while this claim does work in the syntax, it creates problems in the morphology. For example, characterizing the well-known "spurious se effect" in Spanish simply cannot be done without reference to 3rd person. Inspired by alternatives to underspecification that have emerged in phonology (e.g., Calabrese, 1995), a revised featural system is proposed, whereby syntactic agreement may be relativized to certain values of a feature, in particular, the contrastive and marked values. The range of variation in PCC effects is shown to emerge as a consequence of the parametric options allowed on a Probing head, whereas the representation of person remains constant across modules of the grammar and across languages.