What if a patron wants to find books on a certain subject?

Library of Congress Classification System: B

B     Philosophy, Psychology, Religion (Lower Level)

B: Philosophy (General)

BC: Logic

BD: Speculative philosophy

BF: Psychology, Parapsychology, Occult sciences

BH: Aesthetics

BJ: Ethics, Social usages, Etiquette

BL: Religion, Mythology

BM: Judaism

BP: Islam, Bahai Faith, Theosophy, etc.

BQ: Buddhism

BR: Christianity, Church history

BS: Bible

BT: Doctrinal theology

BV: Practical theology

BX: Christian denominations