A Zirkel (German for 'circle', as in a circle of friends) is a monogram used in European student societies in countries such as Germany, Austria, Switzerland, Belgium, Hungary, Latvia, Estonia (Studentenverbindungen) as a post-nominal letter.
A Zirkel consists of intertwined lines, followed by an exclamation mark if the society is still active.
Examples: Meaning of v-c-f: Meaning of e-f-v: The members of the Studentenverbindung use the Zirkel as sign on Couleur or other things e.g. beer glasses etc.
If a member signs in affairs of its Studentenverbindung, it places the Zirkel after its signature.
This use is similar to the use of postnominals in English-speaking countries.