Always have your Oyster ready. Apologise about everything. And never, ever make eye contact. These are the unspoken laws for living in London, but it looks like we might have to update the rulebook.
This week the Centre for London called for a 'civility code' to be introduced to shift our reputation as a city full of sour faces, swearing and smartphones. The think tank suggest that by tackling city-wide bad behaviour such as aggy cyclists and slow walkers we can make London a better place to be.
So with that in mind: what rule would you make everyone in London follow?
Whether it's a strict ban on anyone boarding the Central line without deodorant or a price cap on pints, we want to hear your one rule for a better London. Add your submissions anonymously in the form below, and the best entries for a brighter city will be featured in Time Out magazine.
While we're on the topic of bad behaviour, take a look at what unacceptable breaches of London etiquette you lot confessed to.