In addition individual witches add their own personal material. This book must be kept secret at all times.
However sad to say some witches have gone public with their Book Of Shadows over the years. In true tradition only one copy of a Book Of Shadows should be kept for a coven. This is usually held by the High Priestess or High Priest.
The book of shadows should only ever be hand written. The secrets in the Book Of Shadows are limited to the witches position in the hierarchy.
Information in the Book Of Shadows is passed out as the witch progresses through the ranks of the coven. If a witch leaves the coven the Book Of Shadows must stay with the coven.
Very little is known about "books of shadows" before the 20th century. In earlier times the secrets were generally passed down through the generations orally.
Some hereditary witches claim their ancestors recorded secret spells and lore in little books. One of the first book of shadows to be published was Charles Godfrey Leylands "Aradia" in 1899.
According to tradition a witches book of shadows is destroyed upon their death.
A Witches' Bible: The Complete Witches Handbook
WITCHCRAFT
PARALUMUN