A set of guidelines on which types of images are acceptable for publication on Facebook has reportedly been leaked.

According to the Gawker.com website, the rules tell staff specifically what should and shouldn't be removed when content has been flagged.

Images likely to be removed include those showing "female nipple bulges", "naked butt cracks" or women breastfeeding without clothes on.

However, same sex kissing, "groping" and "foreplay" is allowed.

The leak follows protests from women unhappy that images of breastfeeding were removed.

The site was also accused of homophobia after a picture of two men kissing was taken down.

Gawker.com said the document was leaked by a disgruntled employee at a third party company used by Facebook to moderate users' content.

Protests

Despite the recent controversy users were unaware of exact guidelines used by Facebook to decide which pictures should be taken down.

Images must first be flagged by users before they are brought to moderators' attention.

The document goes into specific detail about dozens of examples of images which should be removed.

Urine, faeces, vomit, semen, pus and ear wax are all banned.

Although cartoon faeces, urine, and spit are allowed.

Snot, both real and cartoon, would also escape the censors, as would deep flesh wounds and excessive blood.

Images of bone, muscles and tendons would be likely to go.

In a statement Facebook said: "In an effort to quickly and efficiently process the millions of reports we receive every day, we have found it helpful to contract third parties to provide precursory classification of a small proportion of reported content.

"We have, and will continue, to escalate the most serious reports internally, and all decisions made by contractors are subject to extensive audits."

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