[3] Germano & Gyatso (2000: p. 240) note a similarity of practice between Chan-like formless meditations and Nyingthik/Menngagde: ...the Seminal Heart or Nyingthik (snying thig) form of the Great Perfection (rdzogs-chen) movement, ...a syncretic Tantric tradition consisting of Chan-like practices of formless meditation combined with exercises that cultivated spontaneous visions of buddhas.
[5] Mañjuśrīmitra's student Sri Singha reedited the oral instruction cycle and in this form the teaching was transmitted to Jñānasūtra and Vimalamitra.
[8] Another feature of the menngagde is the sādhanā of the Seven Mind Trainings (Wylie: blo sbyong don bdun ma) Capriles (2003: p. 103) identifies the sādhanā of the "Seven Lojong".In the cycle of Dzogchen Nyingthik teachings, there is a series of successive reflections called “the seven mind trainings” or seven lojong, the effect of which is similar to the one attributed to the “four reflections:” that of causing one’s mind to become integrated with the meaning of the teaching.
[9]Menngagde itself is sometimes said to have been further divided by Sri Singha into four categories, called the "Four Cycles of Nyingtig" (Wylie: snying thig skor bzhi).
They are the: Variations of the name of the fourth section include the Secret Heart Essence (gsang ba snying thig), the Most Secret Unexcelled Nyingtig (yang gsang bla na med pa snying tig), the Innermost Unexcelled Cycle of Nyingtig (yang gsang bla na med pa'i snying thig skor), the Most Secret and Unexcelled Great Perfection (yang gsang bla na med pa rdzogs pa chen po), the Most Secret Heart Essence (yang gsang snying thig), the Most Secret Unsurpassable Cycle (yang gsang bla na med pa'i sde) and the Vajra Heart Essence.