Yes, the railway website does not mention about this quota and various other quotas like Defence, Foreign Tourist, etc and there is no way to find availability under such quotas in the official railway site. It is not true that this quota is not utilized at all. If you check the availability under this quota a few hours before chart preparation for a train, you will find there is some movement.People who have contacts with higher officials and ministers mainly make use of this quota as they are aware of this.But yes, many times this quota is not completely utilized as very few people are aware of this.