While Spirit Airlines is not the only airline requiring appropriate footwear and clothing from its passengers, it appears to be the only one whose refusal to transport policy includes offensive tattoos.
American Airlines’s contract of carriage declares that passengers must “dress appropriately” and that “bare feet or offensive clothing aren’t allowed.” Delta Air Lines’ explains that a passenger can be refused transportation if their “conduct, attire, hygiene or odor creates an unreasonable risk of offense or annoyance to other passengers.” Similar policies are found in the contracts of carriage of Alaska Airlines and Southwest Airlines. None of them includes tattoos, however.
Although Spirit Airlines provides examples of what “inadequately clothed” might entail, i.e. “see-through clothing; not adequately covered; exposed breasts, buttocks, or other private parts”, there’s no such explanation to help define tattoos that are “lewd, obscene, or offensive.” That said, if you think your clothing or tattoos could be seen as offensive by airline crew or fellow passengers, make sure to have something to cover them with so you can board the plane without any trouble.
The vagueness of airline’s dress codes have led to controversial situations. In January 2022, former Miss USA Olivia Culpo made headlines after she was asked by a crew member to cover up before boarding a American Airlines. At the time, Culpo was wearing bikers shorts, a low-cut black crop top, and an open cardigan. 