It’s in the Shulchan Aruch. It means that if you lose in a Beit Din (Jewish law court), you have the right to ask the judges to explain why they ruled as they did.
When you take a case to the RCC, they insist that you wave your right to this explanation.
This is rare among Beit Din.
Why do the RCC insist so?
Because they don’t want to be sued.
But is this right? Is it Torah?
Let’s talk about cloaking. Let’s talk about Haggadus Eichus.
Let’s say you have a reluctant witness. He doesn’t want to irritate a powerful person with his testimony. So this cloaking device allows the Beit Din to go investigate on their own.
In front of the Beit Din, you can’t argue dismiss testimony by arguing it is "hearsay" or "irrelevant." There is no statute of limitations with a Beit Din. The judges will decide if testimony is irrelevant or hearsay. There are no procedural objections in a Beit Din.