In your roundup of interesting, biscuit-related facts (Crumbs! A history of biscuits in 15 fantastic facts – from flatulence cure to phenomenal fuel, 18 October), you don’t mention the custom of trying to break a ginger biscuit into three pieces while making a wish. My sister’s new boyfriend was visibly startled when her whole family suddenly each seized a ginger snap, closed their eyes and, in synchrony, smashed the biscuit with their elbow. He still maintains that this is a weird ritual practised only within our household, but presumably he did recover from the trauma as he and my sister recently celebrated their 50th wedding anniversary. Anne Liddon Tynemouth, Tyne and Wear • Given that the prime minister, being the attention-loving narcissist that he is, loves the idea of things being colloquially named after him, such as Boris buses, I suggest that the rows of portable chemical toilets that will adorn the laybys of the lorry parks in Kent previously used as motorways should be known as Boris bogs (Roadside portable loos planned for lorry drivers delayed by Brexit checks, 14 October). Steven Julians Romford, London • When Andy Burnham next addresses the nation (Boris Johnson threatens to force tier 3 on Manchester leaders, 16 October), can he please be preceded by Donna Summer and Barbra Streisand singing No More Tiers (Enough Is Enough)? Jodie Payne Yelverton, Devon • I was concerned to see the government advertisement about changes to rules for endangered species appearing in the Feast supplement (17 October). Is this advance notice of even-harder-to-source ingredients in recipes? Steve Mathieson London • Re the article by Larry Elliott (Boris Johnson’s split from Brussels echoes Henry VIII’s break with Rome, 18 October, can we now expect no deal followed by the dissolution of the ministries? Austen Lynch Garstang, Lancashire • Join the conversation – email guardian.letters@theguardian.com • Read more Guardian letters – click here to visit theguardian.com/letters