|"Is this all real? Or has this been happening inside my head?"
The subject of this article is a real-life person, company, product, or creative work that has been mentioned "in-universe" in a canon source. The Harry Potter Wiki is written from the perspective that all information presented in canon is true (e.g., Hogwarts really exists), and, as such, details contained in this article may differ from real world facts.
The Book of Common Prayer and Administration of the Sacraments and other Rites & Ceremonies of the Church according to the use of the Church of England together with the Psalter of Psalms of David of David (full title The Book of Common Prayer and Administration of the Sacraments and other Rites and Ceremonies of the Church according to the use of the Church of England together with the Psalter or Psalms of David pointed as they are to be sung or said in churches and the form and manner of making, ordaining, and consecrating of bishops, priests, and deacons, but most usually referred to as simply The Book of Common Prayer) is an Anglican prayer book written by Thomas Cranmer, a leader of the English Reformation and Archbishop of Canterbury.