While Facebook has long forbidden groups it deems to be terrorist organisations from posting content on its service, the company specified that it will remove content that expresses support for such groups or praises their leaders.
Facebook also made it clear that images "shared in revenge or without permission," often referred to as "revenge porn", were forbidden. But photos of women breastfeeding, post-mastectomy scarring and images of paintings and sculptures with nude figures were permissible.
The clarification comes as social media companies such as Facebook and Twitter - the micro-blogging website - grapple with self-regulating technology that is as easily used for harassment and online bullying as it is for sharing sports videos and news articles.
"Having a voice is not some absolute state. It's not the case that you either have a voice or you don't," Facebook Chief Executive Mark Zuckerberg said in a post on his Facebook page on Sunday.
Zuckerberg said Facebook was not actually changing any of its policies or standards, but merely providing more guidance.
"People rightfully want to know what content we will take down, what controversial content we'll leave up, and why," the Facebook CEO wrote.
Images of graphic violence and nudity have long been problematic for Facebook.
In 2013, the social network said it would use a broader set of criteria to determine when gory videos are permitted on the site after a video of a masked man beheading a woman in Mexico prompted an outcry. The company has also been criticised for allowing pages that glorify violence against women.
Militant groups such as Islamic State have increasingly used social media to spread their message.
Facebook also said on Sunday that it recorded a slight increase in government requests for account data in the second half of 2014.
Requests for account data increased to 35,051 in the second half of 2014 from 34,946 in the first half, with requests from countries such as India rising and those from others, including the United States and Germany, falling. (govtrequests.facebook.com)
(Additional reporting by Shivam Srivastava and Supriya Kurane in Bengaluru) - Reuters