Reiter and<cite> Dale (1995)</cite> pointed out the notion of 'PreferredAttributes' (e.g. Type, Size, Color etc) which is a sequence of attributes of an object that human speakers generally use to identify that object from the contrast set. We assume that the initial description of an entity is following this sequence (e.g. "The large black dog") then the later references will be some subset of initial description (like "The dog" or "The large dog") which is defined as the prefix of the initial description.