Recently, in Singapore, I was running late. Check-in and the flight were closed but I managed to negotiate a boarding pass and get through security screening and immigration with my large suitcase in tow, a suitcase far too large for carry-on baggage. I had to push it through the X-ray machine when it didn't fit first time. At the gate, I advised the airline staff that my bag was a "pram". The gate staff responded that I couldn't take it on board. A metaphysical discussion followed; when could a bag be considered a pram and a pram considered a bag? In the end, they were convinced my bag could be a pram and I promptly boarded the flight with my "pram" checked in at the gate.