• Virgin America

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There are some very unusual airline regulations out there, but they are not state secrets. Go to any airline's website and look for its Contract or Conditions or Carriage, often found at the bottom of the homepage under "legal." 

Most of the rules are standard stuff that governs everything from ticketing to take-off delays, but there are some fascinating nuggets. Here are some of the odder ones:

  • 1. Virgin America's clothing rule

    Virgin America

    The San Francisco-based carrier has a pretty lenient dress code, but it does have some standards, since it refuses to transport any passenger "who is not wearing both top and bottom apparel." Alaska Airlines has a similar rule but gets into a little more detail, explaining that "the midriff may be uncovered." By the way, most airlines also say no to bare feet.

  • 2. American Airlines' odor rule

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    Ever had a stinky seatmate? There's a rule about that at American, which states the carrier can refuse to transport a passenger (and pull him/her off the plane) if the individual "has an offensive odor." If that sounds farfetched, keep in mind that an Air Canada Jazz passenger was booted from his flight in 2010 due to what fellow flyers described as a case of "brutal" body odor.

     

  • 3. Alaska Airlines' behavior rule

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    Alaska Airlines, like most carriers, bars passengers from engaging in abusive or belligerent conduct, but it also singles out "verbal harassment related to race, color, gender, religion, national origin, disability, age, ethnicity or sexual orientation" as a reason to give offenders the heave-ho.

  • 4. United Airlines' exotic service animal rule

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    While airlines allow passengers to bring service or emotional-support animals on planes, what's interesting is the range of critters deemed acceptable or unacceptable. On United, dogs and monkeys get a thumbs-up, but snakes, ferrets and spiders are unwelcome guests. Rules like this make you wonder if someone actually tried to fly with a support snake, but we could find no record of such an attempt.

  • 5. Delta Air Lines' clean antlers rule

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    If you want to bring a rack of antlers on your next Delta flight, no problem. Just make sure they’re not dirty. Delta says antlers "must be as free of residue as possible," plus you have to wrap up the skull and protect the tips. After all that, you also have to shell out the $150 antler transport fee.

  • 6. JetBlue's no valuables rule

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    Actually, nearly every airline has this rule: Valuables are not allowed in checked bags. That doesn’t really stop anyone, but if valuables go missing from a bag the airline can say, "We told you so." In other words, they're off the hook for your loss (but since I'm not a lawyer, you might want to consult one). 

    What is a "valuable"? JetBlue's rule is more explicit than most: Furs, paintings and jewelry, of course, but also humdrum stuff like CDs, sunglasses, dolls, maps, mirrors, musical instruments and even make-up. You'll never worry about this rule if you take my advice and leave all your valuables at home. If that's not possible, keep them on your person.

Rick Seaney is an airline travel expert and the co-founder of FareCompare.com, an airfare comparison shopping site