Formalities for issue of donation coupon by charitable trust

A public charitable trust registered under the Societies Act in Mumbai and u/s 12A of Income Tax Act running a school and a college is in the process of construction of new college building within its compound.

For the said purpose, the trust wishes to issue donation coupons in the denomination of Rs. 500 and Rs. 1000. Such receipts will be credited to the corpus fund/building fund of the trust. What are the legal formalities, if any, to be fulfilled to issue such coupons?  Also, whether the details of the donor who purchase such coupons are required? If so, then what details are required?

Thanx in advance for your replies