As far as any employer is concerned if its employee falsely declare his or her personal particulars when asked then he or she would be terminated once it is discovered.
False declaration of personal particulars is not rampant amongst most employees or would be employees but there will always be a few who would resort to it. Why people don't want to declare the truth? Reason is, the would be employee would not be employed or the serving employee may get the boot. In not telling the truth,one must be prepared for the worst.
There were crew in the past who were dismissed from service because of false declaration. One serious case was of a trainee steward who did not declare he was convicted of a crime involving drugs. He was sacked when the company discovered the truth. Then there was a case of a stewardess "Molly" who were fired because she did not declare she had a child. This story was told on page 18 of my book "Fasten Your Seat Belts".
There were other cases too and most were fired once the truth was discovered.
Recently there was another stewardess like Molly, was fired because the airline found out she has a child and did not declare when she first joined the company.
The union people did a wonderful job by managing to persuade the company to reinstate her. Don't ask me how the union managed to save her but it did and that matter most.
If I was the stewardess, I would be eternally grateful to union leaders like Alan Tan and his committee members. Kudos to Alan and Heart Party!