This paper discusses the classification of null instantiation phenomena in Construction Grammar and proposes a different treatment of so-called free null instantiation (FNI). Based on e.g. control data, different types of alleged FNI are shown to be more accurately classified as definite (adjunct control), generic (e.g. tough constructions), or unspecified for interpretation (e.g. passives). A striking pattern is that general constructions, such as infinitives and gerunds, license unspecified null instantiation (simply NI), whereas more specific control constructions are associated with a definite (DNI) or generic (GNI) interpretation. Hence, the paper proposes a null instantiation taxonomy that distinguishes (unspecified) NI and the specific subtypes definite (DNI), indefinite (INI), identity of sense (ISNA), and generic (GNI) null instantiation.