Last year, on a Turkish Airlines flight bound for Istanbul from Tel Aviv, Jo-Ann Mort encountered an agitated Hasidic man who had been assigned the seat next to hers. Ms. Mort overheard him ask another man, a Reform rabbi in the next seat of their row, if they could switch places. Adhering to the strictest interpretation of Jewish law, the Hasidic man did not want to sit beside a woman who was not his wife. The rabbi said no, so the man asked several other passengers to change seats with him until one young woman finally agreed. Writing about the episode later in Haaretz, the Israeli newspaper, Ms. Mort described a sense of profound irritation that left her scolding the young woman for her submission.

Eventually Ms. Mort became involved with the Israel Religious Action Center, the public and legal advocacy arm of the Reform movement in Jerusalem that had been keeping a tally of these kinds of incidents. Ultra-Orthodox men, the group determined, were regularly asking women on planes to move, especially on flights between New York and Tel Aviv, and especially around Passover and the fall holidays. So, this year, in anticipation of Rosh Hashana, the organization created a billboard that it hoped to post in El Al’s passenger waiting area at Newark Liberty International Airport, which read: “Ladies, please take your seat … and keep it!” The ad went on to explain that requiring a passenger to switch seats on the basis of gender was illegal.

Last month, the Port Authority of New York and New Jersey, which determines what ads can and cannot be displayed in its airports, rejected the proposed ad on the grounds that it violated several of its guidelines, chief among them a requirement that promotional content refer only to products or services, and another that bars political or religious messaging. Similar rules are maintained by authorities around the country and have increasingly come under First Amendment scrutiny for a system of application that can seem arbitrary and illogical. Often, allowances will be made for “public service announcements,” but what constitutes public service is left entirely up to bureaucratic discretion.

On the face of it, an ad informing women, in a secular context, that they don’t have to bow to the imperatives of a religious patriarchy would seem to qualify, but the broader mission of administrators is to protect a range of sensitivities that ultimately become unclassifiable. The “I Love New York” campaign, for instance, appears at La Guardia and Kennedy Airports under the rubric of public service, according to the Port Authority, but if you happen to have had a disastrous honeymoon in the Adirondacks followed by an expensive divorce, you’re unlikely to feel served by an image of Saranac Lake.