DP's exist in many ER trains for eg,Coald field Exp,Agnibeena Exp,SDAH ASN Intercity Daily Passenger travels in specified seats just like normal Reserved passengers,as there is No dedicated Exp b/w BWN-HWH so in EMU they work as DP.But in this 08.40 Local I've seen vendors also use so its not true that Other than DP's nobody is allowed.