Debrett's, mentioned by Louisa in dialogue, is a book published by a British professional coaching company, publisher and authority on etiquette and behavior, founded in 1769 with the publication of the first edition of The New Peerage. The company takes its name from its founder, John Debrett. Their Debrett's Peerage & Baronetage is a book which includes a short history of the family of each titleholder, was previously published roughly every five years. The last printed edition was the 2019 and 150th edition, published in the company's 250th year.