The Library's classification system is unique, having been devised specifically for its purpose by the Founders (who based it upon the Bliss system), and formally copyrighted in 1990. It provides far more subcategories than would the Dewey decimal classification system. It is entirely alphabetical, the first two letters being the category code, the remaining three being the first three letters of the author's surname (with precedence rules for such names as macDonald, tenEyck or duMaurier).
Because the system is lengthy and detailed it is not reproduced here. It covers all esoteric subjects, including (but of course not limited to):
Astrology; Arthurian legend; fiction (SF, fantasy, historical and mythological); religions (comparitive, Paganism, Wicca, Hinduism, Buddhism, Islam, Taoism, Christianity and many others); occult teachings; magic (or magick) in numerous categories; divination; Tarot; Runes; reincarnation; Qabala (spelling optional); UFOs; ESP; astral projection; channelling; clairvoyance; philosophy; psychology; prophecy; Earth mysteries; environmental issues; sustainable living; alternative technology.
The classification system is sufficiently flexible to allow the creation of new categories, which is done whenever a subject group appears to require subdivision.