This empirical study examines the functions of indefinite noun phrases in four types of legal texts in French, namely in textbooks, legal articles, judgments and laws. Whereas in textbooks and laws, indefinite noun phrases are chiefly used in nonreferential, predicative functions, in judgments they mainly appear in a referential, specific function; in legal articles they account for a more evenly distributed set of functions. To capture the characteristics of all the different functions of indefinite NPs in legal texts, L. proposes a mental space model.