Terms of impoliteness, rudeness and profanity are segments of vocabulary which old Chinese dictionaries, glossaries or encyclopaedias are not introducing in their full varieties. For this reason it is a kind of rarity when one finds a bunch of expressions apparently of vernacular origin, and it is even more extraordinary that they are not only listed in Chinese but being a part of a bilingual glossary included in the largest Chinese military compilation, the Wu Bei Zhi (i 武備志), they are provided with their Middle Mongolian translations. The author presents a study introducing the related vocabulary from both sides of the glossary and alongside he analyses the likeliness of their actual use by the time of compilation from the point of view of historical pragmatics.