Yes, us frequent flyers keep hearing this time and time again and we just ignore, but for the first time a relative who has done a lot of flying got denied boarding. She is an Indian citizen and was going to fly a mix of QR and AY. QR was ready to let her board, but the checkin agents said they recently had a similar situation where AY denied boarding. So she cancelled her ticket and rebooked for another day.

The problem is her name is AAA BBB CCC, but in her passport, the box for "Given Name(s)" had AAA and in the box for "Surname" she had "BBB CCC". However her ticket had AAA as first name and CCC as last name. We looked through passports of some of our Indian relatives and many seem to have this issue. I guess the reason why there is an "(s)" for Given Name is to put any middle names. The Surname box does not have any "(s)". We noticed this is passports of other countries as well.

Another relative who had a similar type of passport, said she experienced problems getting a US visa and had to change her passport just for this, so if you about to get a new passport, consider this issue.