I didn't pay any attention to my boarding pass on my outbound flight, but on the return this morning out of PHL, below my name the word SIGNATURE is there. When I got to security, they said I get to go thru the smaller line because of it, which I guess was the First Class line, etc. I dug out some of my old boarding passes, and they have Dividend Miles underneath my name. My account number is on the bottom of the ones that say Signature. Here is a link to a picture of what I mean:
http://i35.photobucket.com/albums/d1.../signature.jpg

So can anyone clue me in as to what it means?