This is a weekly class from Deer Park Monastery on the topic "The 40 Tenets of Plum Village" and it is based on a book called Plum Village Looks at Vulture's Peak written by Thich Nhat Hanh. The book describes the essential characteristics of Plum Village practice and teachings.
For an English translation of the tenets themselves, follow this link.
In this class Brother Phap Luu discusses the 9th tenet: "The Three Dharma Seals are: impermanence, non-self and nirvāṇa. We can uphold Four Dharma Seals or Five Dharma Seals with one condition: that they include nirvāṇa."
Read the Discourse to Channa here.