In Tibetan Buddhism, the "Red Hat" sects or schools include the three oldest of the four main schools, to wit:

The Kagyu school, also known as the "Oral Lineage" and "the Spotless Practice Lineage" school, is one of four major schools of Tibetan Buddhism, the other three being Nyingma (Rnying-ma), Sakya (Sa-skya), and Gelug (Dge-lugs). if (window.showTocToggle)...

The 41st Sakya Trizin, the head of the Sakya school This articles concerns the Sakya school of Tibetan Buddhism. For information on the ancient Śākya tribe, see Shakya. The Sakya (Tibetan: ས་སྐྱ་) school is one of four major schools of...

The Nyingma tradition is the oldest of the four major schools of Tibetan Buddhism (the other three being the Kagyu, Sakya and Gelug). "Nyingma" literally means "ancient," and is often referred to as the "school of the ancient translations" or the "old...

The newer Gelug school is known as the "Yellow Hat Sect".