On Friday, Twitter released details of its global ban on political advertising. The ban will go into effect on November 22 and prohibits any ads that mention specific candidates, elections or legislation.

Also included under the ban are ads from PACs or 501(c)(4) nonprofits, a category that includes political messaging groups.

However, Twitter will allow what it calls “cause-based” ads that “educate, raise awareness, and/or call for people to take action in connection with civic engagement” or issues that have some overlap with politics, such as economic growth. Cause-based ads will face certain restrictions that limit advertisers’ ability to target their ads to specific user demographics.

The ban comes as social media companies face scrutiny over their ad policies going into the 2020 presidential election. Twitter cautioned that the rollout of the ban would almost certainly carry risks.

“We’re absolutely going to make mistakes here,” Vijaya Gadde, Twitter’s legal and policy head, told Buzzfeed in an interview. “But we firmly believe that it’s better for us to start getting it right and giving people ways to tell us how it’s wrong.”

Twitter CEO Jack Dorsey’s announcement of the ban was seen as taking a shot at social-media rival Facebook, which permits political ads even if they include false or misleading information.

“This isn’t about free expression. This is about paying for reach,” Dorsey wrote on his Twitter account on October 30. “And paying to increase the reach of political speech has significant ramifications that today’s democratic infrastructure may not be prepared to handle.”

Facebook’s ad policy has come under scrutiny from progressives, with Senator Elizabeth Warren (D., Mass.) suggesting the company would help the Trump campaign win reelection with what she asserted were misleading campaign ads.

“Facebook is actively helping Trump spread lies and misinformation,” Warren wrote on Twitter. “Facebook already helped elect Donald Trump once. They might do it again—and profit off of it.”