Please do not create more than one NIC handle per individual.
Once you have created a NIC handle for yourself, it is your responsibility to keep the details in the AUNIC database updated (which you can do using editUser, as long as you still have your AUNIC key.
If you do not keep a current email address in the AUNIC database, then there is a risk of other people being able to find out your key.
You may use the same NIC handle for multiple domains or as you change organisations.