We mourn Prof. Dr. Ulrich Ammon: The pioneer of sociolinguistics, who passed away at the beginning of May. One of the focal points of his research was the examination of the different varieties of the German language. He also wrote a book about these varieties, which the ÖSD utilises. The reference book consists of 12,000 words and phrases, which are recognised as a standard in the respective countries and regions. It is internationally unique and considered extraordinary.