University graduates hoping to get a job as an investment banker in London could be disappointed if they wear brown shoes to their job interview. A new report highlights how the investment banking industry in the UK follows centuries-old, unwritten rules about how bankers should conduct themselves. The study was undertaken by the British government's Social Mobility Commission. Researchers looked at how the industry selected people in job interviews. They found that the industry was governed by "relatively opaque" codes of conduct. They wrote: "For men, the wearing of brown shoes with a business suit is generally considered unacceptable…within investment banking.