Context: The Book of Concord is the historic doctrinal statement of the Lutheran Church, consisting of ten credal documents recognized as authoritative in Lutheranism since the 16th century. However, the Book of Concord is a confessional document (stating orthodox belief) rather than a book of ecclesiastical rules or discipline, like canon law. Each Lutheran national church establishes its own system of church order and discipline, though these are referred to as "canons."

Question: What is a fundamental collection of documents of the Lutherans?
Answer: The Book of Concord

Question: Beginning in what century was the Book of Concord a central part of the Lutheran Church?
Answer: 16th

Question: What kind of statement is the Book of Concord?
Answer: confessional

Question: What are the legislative systems of various Lutheran institutions called?
Answer: canons

Question: What kind of belief is the subject of the Book of Concord?
Answer: orthodox

Question: What is the fundamental collection of documents of the Catholic Church?
Answer: Unanswerable

Question: What book has been recognized as authoritative since the 1600s?
Answer: Unanswerable

Question: What book has not Orthodox beliefs?
Answer: Unanswerable