Hi rising_star:
Thanks for your inputs on queries. Could you please explain the following quoted point a bit more elaborately. I did not understand the meaning of 'potentially negative impact', as I will anyway not join the school. Also what do you mean by "I wouldn't chance it personally".
""No, you wouldn't need a formal release but it could potentially reflect negatively on you. I would just wait until the 15th to notify everyone (via email, obviously) and then mail things later. Often accept/decline is handled by the department's Director of Graduate Studies... I wouldn't chance it personally.""
I have one more query. Suppose I accept funding offer of a school well before 15th April and then receive another offer on 14th April; then will it be sufficient enough to just mail the earlier school that I am not going to join there even if I have given the acceptance earlier. Or I would require a formal release from the earlier school. I mean, just dropping a mail to my earlier school on 14th April to change my decision is sufficient enough?