If a Delta employee goes out of their way to do something for me or I perceive their actions/attitude to be outstanding I either give them a certificate or write a letter. I always include my flight number, but don't include my ticket number. I have two different ways of handling what you are asking. If what they did could be perceived as bending the rules for me or could possibly be negatively turned around, I'm pretty generic and don't go into the details... (i.e. "John Smith really went way beyond what I've seen other CSR's do to get me on flight 456. His attitude was spectacular") If I know what they did was just above and beyond and there would be no repercussions with me detailing the specifics, I do just that" (i.e. "When I mentioned that my laptop battery was about to die, Steve Smith offered to take it up to an empty seat in Business and recharge it. He also offered me a glass of wine while I was waiting for the recharge... Wow.. what customer service")...