Emergency Window - RailFans love it. Why? Go figure. - Anubharadwaj Maharshi

This is already explained in previous posts, here it is again.
A Pooled Quota Waiting List ('PQWL') is shared by several small stations in a particular region, If this quota is exhausted, a passenger is placed in the pooled quota waiting list. Pooled Quotas normally operate only from the originating station of a route, and there is only one Pooled Quota for the entire run. The Pooled Quota is intended to be utilized by passengers travelling from the originating station to a station short of the terminating station, or from an...
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intermediate station to the terminating station, or between two intermediate stations. Such remote location quotas are also provided when there is a very strong demand for the train in question, because of which, without such additional quotas, all seats or berths might be fully consumed by passengers from the originating station leaving nothing available for those wishing to travel from intermediate points. Vacant Pooled Quota berths are automatically tapped by the PRS for booking end-to-end passengers. Passengers in the Pooled Quota Waiting List are cleared against the vacancies in the earmarked Pooled Quota only, or against General Quota vacancies available at the time of charting.