D005150

I used it without problem at a city location in London in April and saved about 15 sterling per day.

After running it through Google and digging through many pages, I'm pretty sure it's some kind of discount tied to American Airlines - not an employee or corporate discount but something that is offered on events that someone has negotiated special pricing for the airfare through American. That seemed to be the one common denominator for all the events that it is was tied to.