Japan Airlines has introduced a feature on its seat booking system that shows where young children are seated.
A "child" icon appears when a passenger is travelling with children aged under two years.
One traveller said the feature let him know where babies "plan to scream... during a 13-hour trip".
But some Twitter commentators urged him to be tolerant, while others said the problem could easily be solved with noise-cancelling headphones.
Japan Airlines' website says the icon "lets other passengers know a child may be sitting there". However, the airline warned the tool was not foolproof, as the icon might not appear if a ticket was booked through a third party or if there was a last-minute change of aircraft.
Even so, venture capitalist Rahat Ahmed sent a tweet on Tuesday thanking Japan Airlines for "warning" him about where children were sitting.
"This really ought to be mandatory across the board, " he said, adding that Qatar Airways should "take note".
"I had three screaming babies next to me on my [New York to Doha] flight two weeks ago," he added.
His tweet attracted a number of responses, with some offering support for the "awesome" website booking feature.
However, other Twitter users urged people to be tolerant.
"They are babies, as we all once were. We need to learn tolerance or will soon start needing a map of seat locations for mouth breathers, droolers, farters, drunks, and perhaps a lot more things in life," said Twitter user.