Southwest Airlines said it will apologize to passenger who was told he would be removed from a flight if he didn't change clothes, the second time in recent months the budget carrier has been forced to do so.

Joe Winiecki, of Largo, Fla., boarded a Southwest flight in Columbus, Ohio, wearing a fictional fishing shop T-shirt which featured the words, "Master Baiter."

Winiecki, who was traveling home, said he was in his seat when an when an employee told him he had to change his T-shirt, turn it inside out, or get off the plane.

Winiecki protested that the airline was infringing on his right to free speech, but changed his shirt fearing he would miss the flight and a day's work.

Southwest spokesman Chris Mainz said Friday the employee made a mistake because the Dallas-based airline does not have a dress code.

The airline apologized this summer after a college student wearing a denim miniskirt and a sweater over a tank top was told to change her outfit or get off a flight departing from San Diego.

Kyla Ebbert, who was 23, told the story on "The Dr. Phil Show." She was read a printed apology from Southwest Chief Executive Gary Kelly on the show.

Ebbert was allowed to fly after agreeing to alter her outfit. The airline offered Ebbert free tickets and tried to make light of the mix-up in humorous advertising.

Ebbert declined the tickets.

After the Ebbert encounter, Southwest President Colleen Barrett sent employees a generally worded e-mail reminding them that the airline has no dress code, Mainz said.

Southwest, like other airlines, has language in its contract of carriage that states it reserves the right to deny service to customers whose clothing is "lewd, obscene or patently offensive."

Airline officials have discussed giving employees more specific examples of what is considered lewd or offensive, Mainz said.