The dress code bars pass travellers from wearing spandex or Lycra trousers, including leggings.
Several media outlets also posted stories online that initially lacked the pass traveler information or comment from United. One of the girls, around 10-years-old, who was wearing gray leggings, as able to cover her leggings with a dress she had with her.
The airlines later released a statement clarifying their position on the issue and said regular customers are still permitted to wear leggings on their flights. The two women denied entry were flying as "pass travelers", meaning they were relatives or friends of a United Airlines employee. Actress Patricia Arquette also got involved, with a series of back-and-forth tweets with the airline.
Normal, paying customers are allowed to wear leggings on flights.
The pants-alternative garment became the focus of worldwide debate after a Sunday night tweetstorm detailing a decision by a United Airlines employee to stop three girls at an airport gate for wearing leggings.
3 girls inspected for wearing perfectly acceptable leggings.
The person involved was a friend of a United Airlines staff member, travelling on a discounted "Pass rider ticket". But a spokesperson for the airline said the girls were traveling under an employee travel pass that requires a specific dress code.
According to the company's policy, "pass riders should use good judgment and common sense" and avoid clothing which could be seen as "inappropriately revealing".
Rick Seaney, CEO of FareCompare, a website that curates deals on flights from around the world, said this type of dress code restriction is common for guests of employees who are receiving free travel.