Pu-erh tea

„Nèi fēi (内飞 or 內飛): A small ticket originally stuck on the tea cake but now usually embedded into the cake during pressing. It is usually used as proof, or a possible sign, to the authenticity of the tea. Some higher end pu'er cakes have more than one nèi fēi embedded in the cake. The ticket usually indicates the tea factory and brand.“

„The terms "Xiao shu" (small tree) and "tai di" (terrace plantation) are often interchangeably used, but they should be given separate meanings. "Tai di" connotes high intensity farming, with the entire slope cleared & terraced to plant hedgerows & use of pesticide & fertilizer. But in many gu shu growing villages, there are also new tea plantations which are too young to be called gu shu (ie. less than 100 years old), but they aren't exactly "tai di" either. Many of these plants are growing next to old trees, in a bio-diverse forest clearing, with lots of space around them, not all are sprayed & fertilized. In the future, they will grow into "gu shu", until then we should call them "shen tai xiao shu" (naturally grown small trees)“