There is a growing body of research focused on task-oriented instructor-manipulator dialogue, whereby one dialogue participant initiates a reference to an entity in a common environment while the other participant must resolve this reference in order to manipulate said entity. Many of these works are based on disparate if nevertheless similar datasets. This paper described an English corpus of referring expressions in relatively free, unrestricted dialogue with physical features generated in a simulation, which facilitate analysis of dialogic linguistic phenomena regarding alignment in the formation of referring expressions known as conceptual pacts.