Creator's Description: This paper examines the nature of the Tibetan Buddhist canonical collections with particular attention to the issues raised by the presence of a significant number of pseudepigrapha (falsely attributed works, including many penned by Tibetans) in the Bstan 'gyur (Śāstra). A detailed case is made for one particular work—the commentary on Āryadeva's Lamp that Integrates the Practices (Caryāmelāpakapradīpa) attributed to Śākyamitra—being of Tibetan authorship, and an attempt is made to identify its author. On the basis of this evidence and the writings of Bu ston rin po che (1290-1364) concerning the policies followed in editing the canonical collections, it is argued that these corpora cannot be considered "canonical" in the sense of being intended to serve as criteria for religious authenticity. Rather, the Bstan 'gyur in particular is characterized by an ad hoc nature, a deference to precedent regarding inclusion of works of dubious provenance, and a drive toward inclusivity—aiming for comprehensiveness, rather than authority.