A nice overview about the quite peculiar ‘Letter of reference’ practice in Germany here:
Unique in a way that not only do employees have a statutory right to written reference, but that the right also extends to have ‘well-worded’ reference. When you really think about it, such an entitlement not only makes good references almost worthless (after all, if every leaving employee gets a good reference, whats the point?). But it also gives employers a statutory right to lie about the employee’s performance. Which is very odd given that in all other respects, employment relationships in Germany are based on absolute honesty and trustworthyness.