We asked for 2 things before you come in:
(2) Any form of identification to identify yourself [try to keep it somewhat unique]
Food court 3rd floor in Tysons Corner is huge. We do not want you to miss the meeting by looking around every table, and at the same time we don't want ourselves to look like fools by looking around for some unknown entity.
So the best way to identify yourself would be to send something like: "Hey, this is str0ke[Artificial Name, not your NAME or SSN]. I would be wearing Defcon 16 T-shirt with blond hair and blue eyes." That should be good enough for us to identify you among the crowd. But if you wanna add description like "I am 6 feet tall." or something else, you are more than welcome to. But if you would mind to provide such details, we cannot identify you or call your HANDLE out loud to determine if it was you.
Hope this clarifies your questions. Do not hesitate to ask more questions? These questions clarifies things that wouldn't happen if we do not get to know what you feel.