At the end of the main sermon the minister who delivered it will ask the other ministers for zeugnis. They are expected to confirm what they had just heard matches with what the Bible says, and then add some of their own thoughts. For the most part this didn't take long, a few minutes a piece and it was time for the fifteen minute closing prayer and the last hymn.
Some ministers had a problem keeping their zeugnis short. One in particular would ramble on and on and on for thirty minutes or more. The one Sunday it had been the bishop's turn to deliver the main sermon. When he asked for zeugnis this minister again kept going and going, finally at the almost 45 minute mark, the bishop leaned forward and said, "I asked for zeugnis, not a sermon." You could have heard a pin drop.
After that, the zeugnis portion of church was much better, the long winded zeugnis giver now became the shortest, barking out only the bare minimum. We didn't mind.