A. Initial Philosophical Considerations To refer is to single out, pick out, specify, select, or uniquely identify a particular (person, object, place, event, or process) as existing in a given domain or universe of discourse and thus to be able to answer the question of who, what, or which one, or, in other words, to say what there is in the given universe of discourse. Reference is carried out by means of tokens of singular terms/expressions (definite noun phrases, proper names, pronouns, and demonstratives) employed by language users in specific contexts or situations (occasions of use, utterance situations). The particular picked out on any given occasion is the referent; the expression used for this purpose is a referring expression; the relation between a token of an expression and the object is the reference. The use by a human agent of a token of a referring expression in a given context for identifying purposes constitutes the act of referring (Strawson 1950; Searle 1969; Chastain 1975). The foregoing definitions yield five dimensions of the study of reference.