Esotericism
In Vajrayāna particularly, Tibetan Buddhists subscribe to a voluntary code of self-censorship, whereby the uninitiated do not seek and are not provided with information about it. This self-censorship may be applied more or less strictly depending on circumstances such as the material involved. A depiction of a mandala may be less public than that of a deity. That of a higher tantric deity may be less public than that of a lower. The degree to which information on Vajrayāna is now public in western languages is controversial among Tibetan Buddhists.
Buddhism has always had a taste for esotericism since its earliest period in India. Tibetans today maintain greater or lesser degrees of confidentiality also with information on the vinaya and emptiness specifically. In Buddhist teachings generally, too, there is caution about revealing information to people who may be unready for it. Esoteric values in Buddhism have made it at odds with the values of Christian missionary activity, for example in contemporary Mongolia.
Read more about this topic: Tibetan Buddhism, General Methods of Practice