I think GD-ASN Weekly is also ISO certified. Amongst all trains to have this certification, this train might be a misnomer since it is a relatively low speed [has 3 loco reversals and traverses via low mps routes] and most importantly, doesn't start/end at very prominent stations. [Gonda and Asansol are big stations but usually long distance trains stop here, they don't usually initiate/terminate from here; except for passengers/EMUs]