Following leggings-gate, United tweeted out its Contract of Carriage and cited Rule 21 and the portion that says it can refuse service to passengers "who are barefoot or not properly clothed." Though, United later stepped that back a bit to specifically point to the pass rider guidelines.
“When taking advantage of this benefit, all employees and pass riders are considered representatives of United," the statement read. "And like most companies, we have a dress code that we ask employees and pass riders to follow. To our regular customers, your leggings are welcome.”
You say potato; they say potato.