The Mother Tantras in the Highest Yoga Tantra section are classified according to their associations with six buddha-families. This section, however, contains two Saṃvara (བདེ་བའི་མཆོག་, bde ba’i mchog) tantras translated by Smṛtijñānakīrti that are not grouped with any one family, but are considered to teach all families equally.