Google ruling: No exposure. One producer wanted to keep the navel exposed but execs had a conniption and fabric and makeup were added to hide the provocative belly button. Similar measures were taken to keep Mary Ann and Ginger decent while stuck on the island.
First navel flashing was Yvette Mimieux in a '64 episode of Dr. Kildare. Later there were a couple Star Trek episodes in '67 & '68 where Uhura and guest star Nancy Kovak slipped by censors. Eventually Cher blew the door wide open on the Sonny & Cher Comedy Hour to some scandal and an article in People
Sunoverbeach wrote: