The newly announced ban on electronic devices, which the U.S. Department of Homeland Security announced Monday, confused travelers, especially after it was followed up by an announcement from Britain on Tuesday about a similar ban.
Homeland Security said the changes were necessary for added security and to thwart potential terrorist attacks on commercial airlines.
Here are six things you need to know to navigate the ban.
1. The U.S. ban does not apply if you're on a flight within the United States.
2. The U.S. ban does apply to flights flying to the U.S. from 10 international airports in the Middle East and Northern Africa.
—Queen Alia International Airport (AMM) in Jordan
—Cairo International Airport (CAI) in Egypt
—Ataturk Airport (IST) in Turkey
—King Abdulaziz International Airport (JED) in Jeddah, Saudi Arabia
—King Khalid International Airport (RUH) in Riyadh, Saudi Arabia
—Kuwait International Airport (KWI) in Kuwait
—Mohammed V Airport International Airport (CMN) in Casablanca, Morocco
—Hamad International Airport (DOH) in Qatar
—Dubai International Airport (DXB) in Dubai, United Arab Emirates
—Abu Dhabi International Airport (AUH), United Arab Emirates
The ban affects foreign airlines that fly nonstop to the U.S. from those destinations.
3. The ban does apply to anything electronic other than a smartphone (but not medical equipment). Homeland Security did not provide details, such as brand name or size, about the type of phone you may take on a plane.
"Smartphones are commonly available around the world, and their size is well understood by most passengers who fly internationally," an online agency statement said.
If you're in doubt, the DHS suggested checking with your airline.
Banned items on flights into the U.S. from affected airports include laptops, tablets, e-readers, cameras, portable DVD players, electronic game devices (bigger than a smartphone) and travel printers/scanners.
4. The electronics ban does not affect anyone flying from the U.S. to those 10 airports or any other airport. If you're flying, say, from the U.S. to Istanbul, you may take tablets, laptops and video game players on board your flight.
But on the return flight from Istanbul to the U.S., everything except your cellphone must be stowed in checked luggage.
5. The ban does apply to fliers "regardless of trusted traveler status," according to Homeland Security. It appears you're not exempt if you are enrolled in Global Entry or TSA PreCheck, which allow you to leave laptops and other electronics in your carry-on luggage during expedited airport screening.
6. After the U.S. announcement, Britain enacted a similar ban with some key differences: If you are flying into Britain from Turkey, Lebanon, Egypt, Saudi Arabia, Jordan and Tunisia, everything but your smartphone must be in checked luggage.
Also, Britain is specific about the size of the smartphone you are allowed to bring on board. It can be 6.29 inches long, 3.6 inches wide and .59 inches thick. Some larger phones may not meet these specs.