"The restrictions and exceptions to the rules on female nipples are extensive and confusing, particularly as they apply to transgender and non-binary people," the panel of independent experts advising the US company said in a conclusion.
The board overturned Meta's decision to remove nipple-baring photos of a trans and non-binary couple who were fundraising on Instagram for gender-affirming top surgery for one of them.
The board argued that Meta's policy, which bans pictures of women's nipples but not of men's, was discriminatory because it was based on a "binary view of gender and a distinction between male and female bodies."
Meta has been told to define "clear, objective, rights-respecting criteria... so that all people are treated in a manner consistent with international human rights standards, without discrimination on the basis of sex or gender."
*Meta (Facebook and Instagram) is banned as an extremist organization in Russia.