That reminds me of a meeting from my old company where they were talking about dress codes. They didn't have a formal dress code, but they were asking people to exercise some discretion.
The government agency I used to work for tried to institute a formal dress code back in the late 1980s. They wanted to require all the men to wear coats and ties. The male employees complained that such a dress code constituted sexual discrimination because they weren't also requiring the women to wear coats and ties. That dress code never happened.