Abstract: Detecting named entities in text has long been a core NLP task. However, not much work has gone into distinguishing whether an entity mention is addressing the entity vs. referring to the entity; e.g., \textit{John, would you turn the light off?} vs. \textit{John turned the light off}. While this distinction is marked by a \textit{vocative case} marker in some languages, many modern Indo-European languages such as English do not use such explicit vocative markers, and the distinction is left to be interpreted in context. In this paper, we present a new annotated dataset that captures the \textit{address} vs. \textit{reference} distinction in English, an automatic tagger that performs at 85\% accuracy in making this distinction, and demonstrate how this distinction is important in NLP and computational social science applications in English language.