The one thing Canadian travellers can be sure of carrying onto U.S.-bound flights is a heavy case of confusion.
Somehow, in releasing exactly 13 items travellers can take on board, Transport Canada has also let loose a flood of queries on everything from toys and books to mitts and tuques.
Even a child's Nintendo DS will come under scrutiny and could leave parents scrambling for alternative entertainment. "Do you need it between Montreal and Boston?" spokeswoman Maryse Durette asked. "Not necessarily. Between Montreal and Los Angeles? It might be an important tool for the parent to have."
So who decides?
"The screening people have somewhat a discretion in there," she said. "We believe the screeners are well-trained and they can exercise common sense."
The government list was a reaction to uncommon times. A Nigerian man's attempt to blow up a Detroit-bound passenger plane on Christmas Day by concealing weapons in his underwear resulted in the Canadian government banning carry-on luggage for U.S.-bound flights - with the exception of items on the official list, including coats, crutches, small purses, laptops, cameras and medication.
So, can you take an iPod through security? "If that's the only thing you've got and you don't have 300 bags, I'm pretty sure they'll say that's fine," Ms. Durette said. How about an iPod and backpack? "Well, your iPod can fit in your backpack or your small purse, so you're good," she said.
Coats are on the list, but there's nothing about winter accessories. "We're in Canada, after all. We're travelling in winter, and if you have your hat and your mitts, they won't be thrown out in the garbage... That's where common sense comes [into]play," Ms. Durette said. "What we want to do is limit the amount of allowed carry-on in order for the check lines to move fast but securely."
It's not known whether Transport Canada will expand the list, but for now it offers the following advice: Bring little to nothing; if you don't need it, check it; and get there three hours ahead of time so you can check in what's not permitted as carry-on, rather than being forced to toss it. After all, while Ms. Durette suggested some wiggle room in the articles allowed, Mathieu Larocque, a spokesman for the Canadian Air Transport Security Authority, declined to specify what those additional items might be.
"Our screening officers have very strict rules," he said, "and we don't typically discuss these publicly for security reasons."
With a report from Jill Mahoney