Manjushrimitra received the transmission of all Dzogchen teachings from Garab Dorje and subdivided them into three series: Semde, Longde and Mennagde. The three series are three ways of presenting the teaching, each with its corresponding methods of practice; the aim of all three, is to lead to final realization.
In Semde, the “mind series”, the practitioner is introduced through personal practice to the nature of mind in order to have a concrete experience of it.
Longde means the “series of space”. In this instance space refers to the primordial dimension of emptiness which serves as a base for manifesting the clarity of the practitioner.
Mennagde, the essential series of “secret instructions” or Upadesha, comprises special teachings and methods based on the experiences of masters, with the aim of helping the practitioner progress up to complete realization.