The I Ching (Book of Changes) is best regarded as an elegant system of divination. In general use it is set in motion by throwing three coins six times. The resulting hexagram is a reply to the question asked. Understanding, not the printed line-text alone, is what reads the reply.
Within the International Nath Order this book is a working oracle, not a Chinese hobby and not a sister science to Indian astrology. Shri Gurudev Mahendranath used it as a medium of communication with the Cosmos and wrote a short bow to the Cosmic Oracle before the coins. He also read yoga in the trigrams. Sri Kapilnath’s note is the INO reading of how to ask. This page names the book. It does not teach sixty-four hexagrams.