Gouskova, Maria. 2007. DEP: Beyond epenthesis.. Linguistic Inquiry 38:4, pp. 759-770.
DEP is often informally characterized as a constraint against epenthesis, but its actual effects are more diverse. In the domain of base-reduplicant correspondence, DEP can have the effect of blocking deletion in the base, as in Tonkawa reduplication. In the domain of output-output correspondence, DEP in effect requires deletion of underlying material in derived forms, as in English. These consequences follow straightforwardly from the correspondence-theoretic definition of DEP as a bi-level faithfulness constraint, and they cannot be derived without such a constraint.