I can imagine that you can't do stand-up comedy because they can't control the content.
The talent show is not done at midnight, when the adult comedians perform. The talent show must be PG rates for families.
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No, they do not allow Adult Comedy by anyone except paid performers during the limited access midnight shows. No Stand Up comedy is even allowed during talent night simply to avoid anyone putting in something offensive. That is an iron clad rule and I have never even heard of any exceptions to it.