This is not acceptable, since this woman's nipples are visible. This picture is from Rock 'N' Roll Babylon, which was rejected by the federal prison system.

This is not acceptable, since this woman's nipples are visible. The butts are ok, since they're shown from the side. This picture is from Severo Vargas: Cuenta la historia de la Amazonia. (1860-1992)

This is not acceptable, since it's very clearly a penis, even though it's not attached to a person. This picture is from National Geographic Viajes Edicion Especial Tesoros de Asia.

This is not acceptable, since the woman's nipples are visible. This picture is from National Geographic Viajes Edicion Especial Tesoros de Asia.

This is not acceptable, since the crack of the baby's butt is visible. This picture is from National Geographic Viajes Edicion Especial Tesoros de Asia.

This is not acceptable, since these peoples' whole butts are visible. This picture is from Resumen de Historia del Ecuador.

These examples are acceptable:

This is acceptable, since the man is wearing underwear. This picture is from Rock 'N' Roll Babylon.

This is acceptable, since nipples are covered and side-butts are ok. This picture is from Rock 'N' Roll Babylon.

This is acceptable, since no nipples or genitals are visible. This picture is from Rock 'N' Roll Babylon.

This is acceptable, since the man's genitals are covered. This picture is from Rock 'N' Roll Babylon.

This is acceptable, since the man's genitals are covered. This picture is from Rock 'N' Roll Babylon.

This is acceptable, since male nipples are ok. This picture is from Rock 'N' Roll Babylon.

This is acceptable, since no butts or genitals are visible. This picture is from National Geographic Viajes Edicion Especial Tesoros de Asia.

This is acceptable, since no butts or genitals are visible. This picture is from National Geographic Viajes Edicion Especial Tesoros de Asia.