What is exemotion eligibility certificate no. in exam form

Karan Sharma (article) (64 Points)

06 February 2015  
I have got exemption in Indirect tax in final examinations held in Nov 2014. While filling the exam form for may 15 exams, exemption eligibility certificate no. and date.I would like to know where can i get this certificate.Whether this field is mandatory for claiming exemption.