Volcanohunter, the 15 year rule was enforced by the German trade union for stagecraft and artistic workers in order to ensure a steady job after a certain time in a theatre. They were thinking of opera singers (mainly the chorus) and actors, the rule is not good for dancers, but the lobby inside the union seems to be too small to change it. And there are few dancers who really stay so long with a company, it only applies for the big companies, not for the smaller oder modern ones. As you know, Germany is the country with the most state subsidized theatres in the world - actors and singers keep moving from theatre to theatre after 5 years, after 10 years, so they have lots of possibilities to play King Lear or sing Klytaemnestra
Diane, there is no exception from the 15 year rule, you can add 4 extra years, but after that, a dancer has to be hired for the rest of his working career, that is until he or she is 65 years old.