California Code, Public Utilities Code - PUC § 7657

Every conductor, baggage master, engineer, brakeman, or other employee of any railroad corporation, employed on a passenger train or at stations for passengers, shall wear upon his hat or cap, or in some conspicuous place on the breast of his coat, a badge, indicating his office or station, and the initial letters of the name of the corporation by which he is employed.  No collector or conductor, without such badge, is authorized to demand or to receive from any passenger any fare, toll, or ticket, or exercise any of the powers of his office or station.  No other officer or employee, without such badge, has any authority to meddle or interfere with any passenger or property.