When was Prince's full name known?

I recall reading that Prince’s full name and personal history was a mystery in the earliest stage of his career, and that he wasn’t fully named in public for several years. Is this correct, and if so, what are the details?

I can’t speak for his personal history but I recall his name being known almost immediately. At least the early 80’s, if not before.

Early 80’s seems correct - here’s one from 1982:
http://books.google.com/books?id=jSQEAAAAMBAJ&lpg=PT71&dq=“prince%20rogers%20nelson”&pg=PT72#v=onepage&q=“prince%20rogers%20nelson”&f=false

It’s not like his history was all that obscure. His parents were relatively well-known performers in the Minneapolis area where Prince started his career and a lot of people he worked with were family friends.

I live in Minneapolis and have friend’s whose older siblings went to high school with him. It certainly wasn’t a secret and was well known here

Okay, bad data in the membanks. Erased. Thanks.

I presume the moment the birth certificate was filled out…

It was 1993, when it was finally revealed that Prince’s given names were “The Artist Formerly Known As”.