After 6 months it has to be revalidated for another 6 months by paying commission again .
After 1 year it can not be used for remittances but can be redeemed at PO at par [ commission can not be redeemed ] up to a period of 2 years from date of issuing .
I still am unable to rely on this as this does not show that any Notification was issued to implement it . Plz see last few lines of the document .
Around one month back I was in PO for getting redeemed a few unused IPOs . During a discussion with the Post Master I requested him to show me the rules relating to IPO . It was then that I gathered the Information noted in post #6 .
I am unable to trace this circular which is dated year 1995 .