Dot all the Umlauts
The German version of "Dot all the I's and cross all the T's." To make sure something is done in the proper manner, without even a minor or technical error.
During John Demjanjuk's trial for his infamous WWII-era war crimes, the prosecuting attorney had to make sure to dot all the umlauts in every motion he made before the court.
Umlaut
Umlaut