Organizers for Thursday’s presidential debate in Houston have asked the Democratic candidates not to swear during the three-hour live television event.

In an email sent by the Democratic National Committee and the ABC News, the network that hosts the discussion, the officials warned the candidates not to swear on stage and indicated that, the broadcast will not be on tape delay, according to CNN.

The suggestion comes after Beto O’Rourke has repeatedly used a common vulgar term in his campaign appearances and Cory Booker told CNN the use of “thoughts and prayers’ after a shooting is [expletive].”

Any use of foul language could violate the Federal Communications Commission’s indecency rules, officials warned.

‘We will not be broadcasting on any delay, so there will be no opportunity to edit out foul language,’ the note read. ‘Candidates should therefore avoid cursing or expletives in accordance with federal law and FCC guidelines.’

O’Rourke and Booker, both running close to the middle or bottom of the pack when it comes to race polling, have increased their use of vulgar language.

During a May interview with CNN, Booker raged against the response to a spat of mass shootings.

“More people in my life kind of died in this nation due to gun violence and then all of the wars and revolution wars now. We are not going to give thoughts and prayers, which to me is just [vulgar expletive]. I’m sorry to say it as a man of faith, but I was taught that faith without works is dead,” he said.

An ABC reporter asked O’Rourke, at the New Hampshire Democratic State Party convention on Saturday, if he was planning to swear during the debate.

“Maybe,” he answered.

The debate on Thursday, Sept. 12, will feature only 10 candidates and will only be one night. It’s going to be a three-hour event from 8 p.m.-11 p.m. ET. Candidates will make opening statements but not closing remarks.