Warning! Some readers may find this content disturbing.

Facebook told the Guardian it will allow ‘general expressions of sexual desire but we don’t allow sexually explicit detail’. The devil, as they say, is in that ‘detail’. The documents show moderators what is permitted – and we have included some examples here. But we cannot include images of what is not allowed, because they are too graphic. Many of the files include dozens of examples of pornographic images.

Facebook has had to be quite specific – for instance, it defines ‘groping’ as requiring indentation of the skin. Cupping does not constitute a ‘grope’. Another category we cannot show is called ‘creep shots’. This explains to moderators how some ‘up the skirt’ photos are allowed, and others are not. Any pixelation was added by the Guardian.