When I was travelling by Wainganga Coach attendant said IR will give license for a party to sell/cater food/water when it doesn't have PC for which selling person should be with Uniform and Badge having Details of License to Sell in that particular Train. Observe Few trains for SWR(Weekly) A/C Bedding fellow(Not permanent Employee of IR) itself will sell water with a Badge ( I felt License Holder is trying to Manage with OnBoard staffs for selling that deploying one more)