80g

Obviously it should be serially numbered.Otherwise it would turn out to be one slip issued to numbers..Also there wud be no control on number of slips issued

80g deduction is for donations

Therefore there is no need to specify all the amounts of same category serially, if donations are made to same charity, institute etc. you can show the amount in total if the donations are made to same charity etc.

But in case donation is made to diffrent charities etc. and of diffrent categpries then you have to show it seprately.

Furthur you have to keep all the slips of donation receipt with you (whenever the demand made by A.O, you have to show it)