From The World Cup in Germany.com

City
Berlin ticket machines
By Jon Darch
Aug 14, 2004, 22:44

Ticket "Entwerter"
All tickets must be validated (date and time stamped) at the start of your journey (or first journey, in the case of multi-journey tickets). 

 

You validate ('entwerten') your ticket by inserting it in a ticket stamping machine. 

 

You will find these on station platforms and on board buses and trams. 

 

Plain clothes inspectors patrol all forms of local transport and levy on-the-spot fines to anyone found travelling without a validated ticket (known as  a ‘Schwarzfahrer’).

 

On the spot fines are not less than 40 euros.  Frequent offenders are fined up to 1,000 euros.

 

Public transport tickets

The World Cup in Germany.com - For fans, by fans