TOKYO • Fed up with finding yourself next to a screaming child on a long-haul flight? On some Japanese airlines, a seat map will warn you where potentially bawling babies are sitting.

The facility, offered as part of Japan Airlines’ “Smile Support” travel service for those with infants, is not new, but it lit up the Internet after a Twitter user praised it. “Thank you, @JAL-Official-jp for warning 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 spokesman confirmed the feature, pointing out that it was not a novel offering.

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

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

The revelation caused an Internet firestorm, with supporters and naysayers battling it out. “Answered prayers” was the title of a post on the subject by airline specialist site The Points Guy.

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

Another user pointed out that babies are not the only troublesome travellers. “Will airlines also have maps for obnoxious passengers that drink too much, remove their shoes, hog the armrest or recline in my lap?”

Mr Ahmed reported yesterday that he had arrived in New York after his JAL flight. “Ironically chose to sit next to several babies on my two flights: Some great, some loud. It happens. Some adults were worse,” he tweeted.