For second class II & 2S for unreserved & reserved on "IRI".
Similarly for first class can there be separate notations on "IRI"? like I & FC for unreserved & reserved.
This will also clear the confusion....as...many trains show only 'UNRESERVED'.
e.g. Passenger train with only unreserved second class may be shown with 'II' class
...
more... while EMU train having 1st class may be shown with 'II' & 'I' classes
instead of showing 'UNRESERVED'