Pu-erh tea

„In recent decades, demand has come full circle and it has become more common again for Hei Cha, including Pu-erh, to be sold as the raw product without the artificial accelerated fermentation process.“

„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.“