|"Is this all real? Or has this been happening inside my head?"
The topic of this article is of a real-life subject 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.
Bloomsbury Publishing plc was a British publishing house. They were the British publisher of the Muggle-produced copies of Fantastic Beasts and Where to Find Them and Quidditch Through the Ages made to benefit Comic Relief, working in association with wizarding publishers Obscurus Books and Whizz Hard Books, respectively.