Modern-day doxographical presentations of the Nyingma school are usually based on the system of the nine vehicles ("theg pa dgu"). Emphasis is placed on the highest three vehicles in this scheme, namely Mahāyoga, Anuyoga, and Atiyoga. Generally speaking, these three “inner” yogas correspond to three stages in tantric practice, namely the generation stage, during which the details of the visualizations are stabilised, the perfection stage, in which those visualizations are then employed towards familiarizing oneself with the state of enlightenment, and finally the Great Perfection, the spontaneous accomplishment of buddhahood. Being the second of the three inner yogas, Anuyoga is thus associated with the practices of the perfection stage.