The 2,500 words guidelines for its 1.39 billion active users worldwide Facebook has listed its standards for posts.  Users post everything under the sun and sometimes their imagination runs riot; and the Facebook, which is a communication platform, is impressionable.

The community standards guidelines issued on Monday makes it clear what is allowed and what is not.

"We're trying to strike the balance based on the way our community works," says Monika Bickert, Facebook's head of global policy management. "The landscape is complicated." However, Facebook will still rely on users to report violations of the standards. Facebook has no plans to automatically scan for and remove potentially offensive content.

Terrorist organizations like the Islamic State have long been banned from the service. Along with this prohibition those groups supporting or praising outfits involved in "violent, criminal or hateful behavior" is also banned, the updated rules say.

Threatening people with physical or financial harm, or bullying them by posting items intended to degrade or shame them, is also prohibited. So is anything that encourages suicide or eating disorders.

Pornography and most other nudity is no no on the social media site and now the guidelines says "we remove photographs of people displaying genitals or focusing in on fully exposed buttocks."  It also restricts some images of female breasts if the nipple shows, "but we always allow photos of women actively engaged in breast-feeding or showing breasts with post-mastectomy scarring." Photos of paintings, sculptures and other art that depicts nude figures are also fine.

The company for the first time explicitly banning content promoting sexual violence or exploitation, including so-called revenge porn, which it defines as intimate images "shared in revenge or without permission from the people in the images." (Twitter has also updated its rules to forbid revenge porn.)

The restrictions extend to digitally-created content, unless posts are for educational or satirical purposes. Likewise, text-based descriptions of sexual acts that contain "vivid detail" are forbidden.

Facebook said some users were confused about why complaints had been rejected. However, Facebook adds that it will "always allow photos of women actively engaged in breastfeeding or showing breasts with post-mastectomy scarring".

Images altered to "degrade" an individual and videos of physical bullying posted to shame the victim are now expressly forbidden.

People are allowed to share examples of others' hate speech in order to raise awareness of the issue, but they must "clearly indicate" that this is their purpose.

Users are prohibited from celebrating any crimes they have committed, but adds that they are allowed to propose the legality of illegal activities.

These guidelines allow the Facebook delicately balance the need to ban violent or offensive content without suppressing the free sharing of information among the audience which is diverse in age, cultural values and laws.