Donald Trump at his 2011 Comedy Central Roast. Andrew H. Walker/Getty At Donald Trump's Comedy Central Roast in 2011, comics poked fun at the now Republican presidential nominee on a number of issues, including his hair, wife, family, sex life, and failed businesses.

But, according to Aaron Lee, a writer for the roast, there was only one topic that Trump made off-limits.

Lee posted on List a series of joke subjects that Trump "allowed" — ones that actually made it onto the program — with Trump's only objection being the one topic he explicitly held "sacred."

"The only thing we got from Trump was the request not to say he exaggerates his wealth," Lee wrote, adding that it's standard for Comedy Central Roast subjects to deem certain things off-limits.

Here's the full list of what made it on the roast and the one thing Trump forbade:

ALLOWED: Jokes about Trump's hair

ALLOWED: Jokes about Trump's wife Melania (and his two previous marriages)

ALLOWED: Jokes about Trump having sex with models

ALLOWED: Jokes about the failure of Trump Steaks, Trump Water, Trump Cologne, and other Trump products

ALLOWED: Jokes about Trump's failed casinos

ALLOWED: Jokes about how Trump only became successful thanks to his wealthy father

ALLOWED: Jokes about Trump's weight

ALLOWED: Jokes about Trump being attracted to his daughter Ivanka

NOT ALLOWED: Any joke that suggests Trump is not actually as wealthy as he claims to be

As Vulture points out, Trump allowed comedian Jeff Ross to say, "The Donald and I have a lot in common: We both live in New York, we both play golf, we both fantasize about his daughter."

But if Ross, Lisa Lampanelli, or Seth MacFarlane had joked about, say, Trump's tax returns? That's where our potential next president would have drawn the line.

Watch highlights from the roast below: