Four perfect knowledges

Four perfect knowledges (Wyl. so so yang dag par rig pa bzhi) — part of the twenty-one sets of immaculate qualities.

1. perfect knowledge of meaning
2. perfect knowledge of Dharma
3. perfect knowledge of language
4. perfect knowledge of courageous eloquence

In Mipham Rinpoche's Khenjuk, these are described as the means of maintaining the vast and profound teachings, i.e., the ten topics of knowledge (the vast) and the four seals (the profound).