Commercium
{{distinguish|Res extra commercium|Commercium (Roman)}}
A commercium (plural commercia) is a traditional academic feast known at universities in most Central and Northern European countries. In German it is called a {{lang|de|Kommers}} or {{lang|de|Commers}}. Today it is still organised by student fraternities in Germanic and Baltic countries, as well as Poland.
At a commercium, tables are often placed in the form of a U or a W, and the participants drink beer and sing commercium songs. There are strict and traditional rules that govern this occasion but it may also integrate theatrical and musical aspects. A commercium is the more formal form of the tableround, called {{lang|de|Kneipe}} in German.
The term is derived from the French {{lang|fr|Commerce}} and had been used for any sort of noisy event.{{Cite web|url=http://www.duden.de/rechtschreibung/Kommers|title=Duden entry Kommers}} A Commers gathering consists of speeches, toasts and songs, sometimes arranged pranks as well. The drink of preference is beer. The arrangements are governed by officials ({{lang|de|Chargierte}}) elected by the members of the Studentenverbindung.{{EB1911|inline=y|wstitle=Commers|volume=6|page=774}} The sort of event started to be more formalized after 1871. German associations like firefighters or Schützenvereine started to arrange commercia in the 19th century and still do on special occasions.{{Cite book|url=https://books.google.com/books?id=94byBQAAQBAJ|title=Kommunikationsraum Szenekneipe: Annäherung an ein Produkt der Erlebnisgesellschaft|date=2013-11-11|publisher=Springer-Verlag|isbn=9783663080718|language=de}}
Some special customs include a salamander or {{lang|de|Landesvater}}. The guests rise and having emptied their glasses hammer three times on the table with them. On the death of a student, his memory may be honored with a {{lang|de|Trauercommers}}. The operetta The Student Prince made German students' drinking habits famous during the prohibition, and the rousing chorus of "Drink! Drink! Drink!" was especially popular with US theatergoers in 1924. In the last years of communist Eastern Germany, some students managed to arrange for new founded fraternities, e.g. Salana Jenensis in Jena and organized commercia on the Rudelsburg.Kurt U. Bertrams (ed.): Studentenverbindungen in der DDR. WJK-Verlag Hilden 2006
File:Allianzkommers Einladung 1988.jpg|Invitation to a commercium in Eastern Germany 1988
File:Korporierte Studentinnen in Riga.JPG|Sorority students at a commercium in Riga, 2014
File:Kneipsaal Heidelberger Wingolf.jpg|Heidelberg Wingolf's hall for commercia and roundtables