Indian Railways operates a waitlist to ensure trains are fully booked while simultaneously preventing overbooking. Indian Railways marks whether a patron's reservation is wait-listed or confirmed on his ticket.
Patrons with tickets on the waitlist are only given seats if all other previous patrons placed on the waitlist cancel their tickets. Patrons are also placed on different types of waitlists depending on the type of sleeping accommodations they reserve. According to its website, Indian Railways assigns some tickets as reserved against cancellation, which typically guarantees the patron a seat but not a sleeping berth. Due to the complexity of Indian Railway's waitlist system, patrons are required to make reservations at least 60 days in advance.