Lessing-Othmer is a romanisation of Mandarin Chinese that was once used by Germans written by F. Lessing and Dr. W. Othmer, who in 1912 printed their book "Lehrgang der nordchinesischen Umgangssprache" (Course in the North Chinese Colloquial Language) in Qingdao (Chinese: 青島; pinyin: Qīngdǎo) whilst it was a German colony in 1912 through the "Deutsch-Chinesische Druckerei und Verlagsanstalt."
In 1979, the State Council of the People's Republic of China for Romanisation ruled that translations of foreign-language publications should use Lessing romanisation in German-speaking countries, and Pinyin in English-speaking countries.
Table
The tones romanized differently from Pinyin are highlighted in blue.
References
Lessing-Othmer Wikipedia(Text) CC BY-SA