Ritual of the Writing

This ritual may well be one of the most important related to the use, and preservation of magic and magical knowledge.
All academically inclined or educated magic users know this ritual, albeit in various different forms as the ritual differs not only by the school of thinking or magical tradition but by region, culture and many other factors.

By this ritual a magic user can imbue his own magic into a form of scripture, a book, a stone table, scrolls of papyrus or hide etc.
This allows for basically two things. Firstly it allows the production of a preloaded spell focus, similar to a preloaded wand, rod or stave and secondly it makes it possible to reconstruct and learn a spell from such a script if the ritual was done with that intent.

This also means one can not learn or reverse-engineer etc. any magic from a book that has not been embedded with this intent. So all such books must be written using this ritual. This also means that such a book is written by hand.

There can be a printed version but one can not learn the spell from it, ever. There is something about the Ritual of the Writing that simply missing in a printed copy.
Still some books are still printed using the ritual because prints that have been are said to be more robust, the books more sturdy, less prone to damage and there is even stories about those kind of books being unburnable.