Section 15(13)(i) in First Statutes of the University of Udaipur
(i)The elector shall then put the covering latter along with the enclosed envelope containing his voting paper, in a second envelope in Form 5 (none of the Two envelopes to bear any kind of mark outside) and forward the same in a registered cover addressed to the Returning Officer so as to reach him nos latter than the date and hour notified for the closing of the ballot: