This work argues that the pre-nominal particle mí in combination with an NP in San Martín Peras Mixtec (Oto-Manguean, Oaxaca, Mexico) could be characterized as a definiteness marker. Further, mí occurs with pronouns, where it often receives a reflexive translation. Although ‘mí + Pronoun’ usually requires a local antecedent, many occurrences couldn’t be characterized as reflexive, logophoric, or bound. We are currently investigating the question of what precisely the locality-constraints on its anaphoric behavior are.