Apple has tightened its developer guidelines to ban apps that use AI to create offensive content, as well as those that masquerade as regular apps to pass the App Store review process and then turn into nudify apps, or surface those features prominently.

The company updated its guidelines with strong language around AI and user-generated content, and how app developers should include enough preventative measures to moderate objectionable or offensive content. Apps that host user-generated content are required to filter objectionable material, give users a way to report offensive content, and let users block abusive accounts.

Apps containing hidden or undocumented features are also prohibited on the App Store, including apps that misrepresent their purpose during review and only reveal harmful capabilities — such as ‘nudification’ — after approval, a tactic commonly known as bait-and-switch. Apple said that it will remove apps that add features not present in the version submitted for App Store review.

The iPhone maker has also updated the language in its legal section to reinforce that it will bar apps promoting human trafficking and exploitation of children. Apple said last year its review process blocked over 150,000 apps from reaching users and removed 193,000 developer accounts due to fraud and abuse.

In July, the city of San Francisco ordered both Apple and Google to clean up and delete nudification apps from their app stores. City Attorney David Chiu accused the companies of profiting from these apps through store fees. And in April, a Tech Transparency Project report indicated that both tech giants’ stores hosted multiple nudify apps, some of which were rated as suitable for minors.