Mayday standard procedure if you are going to land with less than minimum reserves. This would make the aircraft a top priority with no go-around to be scheduled. It is a company instruction, but nothing to get excited about. Statistically, every so often a flight will get low like this. Sounds like they were on the ball and well in control of the situation, with an escape route planned and ready. With ATC co-operation, the situation was resolved. But then the word gets out........