A book of shadows is a very important part of wiccan practice. It is usually begun at the start of one's studies and is used to keep a record of information learned about the practice including rituals, spellwork, history, etc. It is often advised to keep it private, and that the owner should be the only one to use it directly. As there is a holy book for Wiccans, the book of shadows is thought to be one's own personal interpretation of the religion. It is used to store useful articles to further one's knowledge. The Wiccan rede is usually printed on one of the first pages. The book of shadows is sometimes linked to or named the "book of doors" or the "book of windows", although they can be different things. They are used by Wiccans who practice alone (eclectic) and others.
An initiate is oathbound to keep the contents of their coven's book of shadows secret. It may only be shown to other initiates, generally to allow new initiates to copy its contents. A book of shadows is written in one's own handwriting, as in times when other means of copying whereas yet un-invented, or prohibitively expensive for many, the only alternative would be to have possession of a book in the handwriting of another initiate, which would risk their exposure should the book be captured. Some traditions suggest that the contents of a book of shadows be written in code; i.e. one of the magical alphabets, depending upon tradition. While the "core" material copied would be identical with that it is copied from, some allow people to add personal additions, but these are sometimes considered separate to the book of shadows, proper. Thoughts and beliefs around the book of shadows may differ between Wiccans due to different branches of the religion.
Various people have tried creating dynamic books of shadows here on Wikia, with limited success and using up various names. The most recent effort is at the Black Book Wiki.
The first and original book of shadows was written by Gerald Gardner and used by his Bricket Wood Coven.
It contains the instructions for the three initiation rituals and the sabbat rituals, among other instructions.
The second book of shadows, the first one to deviate from that of Gardner, was the book of shadows that was written by Alex Sanders.
Gerald Gardner also wrote an earlier private handwritten book that was a predecessor to his book of shadows.
That earlier book is Ye Bok of ye Art Magical.