Previous ATAS post on Iri (link) /blog/post/1496186
As per today article of TOI on ATAS (Alternate Train Accommodation Scheme)
This feature of IRCTC is in its initial stage...and will be implemented and will be available for passenger soon...
They are working on its technical issues which will arrive after implementation
It...
more... also mentioned if 'A' train has waiting list more than 70 for its run then the alternate train 'B' will be given an extra coach which is running on same route after Train 'A' and this will be given to previous train WL passenger...