If you’re planning to fly with Spirit Airlines, you might want to rethink your outfit—or even your tattoos. The airline has just rolled out stricter rules about what passengers can wear or display, and it’s causing quite a buzz.

Spirit’s updated policy now clearly states that travelers wearing revealing clothing or sporting tattoos deemed “offensive” could be denied boarding or even removed from a flight. Think crop tops, sheer outfits, or body art that’s considered “lewd, obscene, or offensive.” But here’s the catch: what exactly counts as “offensive” is still pretty vague.

The airline’s contract of carriage, which outlines the rules for passengers, now includes specifics like no exposed breasts, buttocks, or private parts. However, the tattoo guidelines leave a lot up to interpretation, meaning it’s often up to the flight crew to decide what crosses the line.

This move puts Spirit a step ahead of other major U.S. airlines, which tend to keep their dress codes more open-ended. For example, Southwest Airlines bans “lewd or obscene” clothing but doesn’t go into detail, while Delta and United have similar policies about “offensive” attire.

But Spirit isn’t alone in cracking down on certain looks. In recent years, airlines have turned away passengers for everything from leggings and short shorts to clothes with explicit slogans. Even going braless has been enough to raise eyebrows.

According to travel experts, these decisions often come down to the judgment of airline staff. “What one person finds offensive, another might not,” said a former flight attendant. “It’s very subjective.”

So, before you head to the airport, double-check your outfit—and maybe cover up that questionable tattoo. After all, you don’t want to be the one left behind at the gate.