No Screen Credit for Barbara Eden?

That's a good question. Here is what Wikipedia states:

https://en.wikipedia.org/wiki/Billing_(filmmaking)

"Other unbilled roles feature famous actors or actresses who pop up in a movie as a face in a crowd, a man on a bench, or other 'background' characters, who are given screen time for a brief, but recognizable, moment, such as Bing Crosby and Bob Hope momentarily appearing in a circus audience during The Greatest Show on Earth. They can be recognized, but sometimes are not credited for financial reasons – if they receive credit, they would be due payment commensurate with their fame."

So I guess it boils down to money- if they were credited, they'd have to be paid more.

They're cameos, not all cameos get credited. In fact quite a lot of cameos don't get credit.

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