Public transport is often a hot, noisy, and cramped environment, made worse by passengers with pungent food, questionable hygiene, or giant backpacks. While general rules like letting people off first and not putting bags on seats are widely known, vaguer conventions require more nuance. Etiquette experts from Debrett's, Polished Manners, and the English Manner provide advice on handling tricky situations, such as offering seats discreetly to those who need them more, avoiding manspreading by keeping knees no wider than a tennis ball apart, and refraining from putting feet on seats, as shoes are never clean enough.