Earlier his week I was listening to a recent podcast of QI's No Such Thing as a Fish, and learned something about the Nobel nomination process.
For example, it is not possible to nominate a deceased person for a prize ("From 1974, the Statutes of
the Nobel Foundation have stipulated that a Prize cannot be
awarded posthumously, unless death has occurred after the
announcement of the Nobel Prize.) Thus, Mahatma Gandhi, who was never awarded a Peace Prize, cannot now be nominated.
Regarding the title of this post, there is never a public announcement of who has been nominated for any of the Nobel prizes. And this silence is maintained after the awards ("Information about the nominations, investigations, and opinions concerning the award is kept secret for fifty years.")
Thus, you can tell your friends that you have been nominated for the Nobel Prize in (x), and nobody other than those on the committee can authoritatively contradict you, until 50 years from now.