In a new update to its rules and terms of services, Twitter (NYSE:TWTR) has decided to ban pornographic content on its Vine video-sharing service.

According to Twitter, a small percentage of its users are posting videos that “are not a good fit” for its community, and in response to that, the company has changed some of its rules to crack down on explicit sexual content on Vine. The Vine app, which was launched in January 2013, included a large number of posts with pornographic content, leading Twitter to try out different ways to counter the issue.

“For more than 99 percent of our users, this doesn’t really change anything. For the rest: we don’t have a problem with explicit sexual content on the Internet -- we just prefer not to be the source of it,” Vine said in a blog post on Thursday.

Twitter said that it removes obscene or pornographic images from user-profile photos, header photos and background images, but it does not regulate content on external websites or control tweets that link to content on external websites, including pornography. 

On its support page, Vine identifies explicit sexual content as that which includes “depictions of sex acts, nudity that is sexually provocative or in a sexual context, and graphic depictions of sexual arousal.”

However, it says that the service will allow “depictions of nudity or partial nudity that are primarily documentary, educational or artistic in nature.” According to Vine, videos of nude protesters, a mother breastfeeding her child and nude-modeling in an art class are considered examples of acceptable posts.

Vine said that users violating the new policy could face suspension until they remove the offensive content, while severe or repeated violations of this policy may result in permanent suspension.

“If you see a video that violates our updated policy, you can report it by tapping the button with three dots below the post and selecting ‘Report this post’,” Vine said.