Bemused JAL spokeswoman confirms the seat-booking feature, while also pointing out it is not a novel offering.

A feature on Japan Airlines’ seat-booking system warning travellers of where young children are seated has caused a storm online.

The facility, offered as part of the airline’s “Smile Support” travel service for those with infants, is not new, but still lit up the internet after a Twitter user praised it.

“Thank you, @JAL_Official_jp for warnings me about where babies plan to scream and yell during a 13 hour trip. This really ought to be mandatory across the board,” venture capitalist Rahat Ahmed tweeted.

A somewhat bemused JAL spokeswoman confirmed the feature, while also pointing out it was not a novel offering.

At least one other Japanese airline does the same: All Nippon Airways (ANA), where a spokeswoman confirmed its seat maps have shown where children are sitting “for a while”.

JAL’s maps indicate where infants under two are sitting, with a child icon to let “other passengers know”.

The revelation caused an internet firestorm, with supporters and naysayers battling it out.

“Answered prayers”, airline specialist site The Points Guy titled a post on the subject.

“Nice. But how long before we get upcharged for seats away from said babies?” one user asked.

Another called the map an unnecessary offering.

“Japan Airlines seat map helps avoid screaming babies. Why not just have noise-cancelling headphones?!”

And some pointed out that babies aren’t the only troublesome travellers.

“Can we use the same software to avoid people who eat noisily instead?” one Twitter user asked.

“Will airlines also have maps for obnoxious passengers that drink too much, remove their shoes, hog the armrest or recline in my lap?” added another.

Ahmed reported Friday that he had arrived in New York after his JAL flight.

“Ironically chose to sat next to several babies on my two flights: Some great, some loud. It happens. Some adults were worse,” he tweeted.