The Trump administration announced this week that U.S. airlines will no longer be required to disclose baggage fees as soon as customers start the ticket-buying process. The Department of Transportation (DOT) decision is a direct reversal of an earlier proposal by the Obama administration requiring airlines and ticket agencies to be transparent about baggage fees.

So what does this mean for travelers? Well, when buying a ticket from an airline's website or through a third-party agency like Expedia or Orbitz, you might not see what the cost of checking a bag is when viewing flight prices. It's up to airlines if they want to display baggage costs, so the total ticket price you see might be less than what it actually costs. If you want to compare prices thoroughly between tickets, you'll have to do some digging on your own to find baggage fees (airlines are still required to disclose details about ancillary fees on their website). If an airline doesn't disclose its baggage fees and you're checking a bag, you won't know how much it costs until you enter your credit card information—or until you get to the airport.

As reported in The Hill, the DOT is also withdrawing a proposal to force airlines to disclose how much revenue they make from ancillary fees, like checking a bag and choosing a seat with more legroom. The Trump administration has said that such regulations have "limited public benefit."

The DOT decision comes right after Delta announced that it will charge basic economy passengers baggage fees on flights between the U.S. and Europe or North Africa. Previously, basic economy passengers could check one bag free of charge on international flights, but now, it will cost $60 for the first bag and $100 for the second. And since airlines are no longer be required to disclose those fees upfront, a ticket to Europe could cost $100 more than what's displayed to customers when choosing their flight.