We're in VA just over an hour from D.C. and we're rolling out in around 8 hours so I can't help but I think posting the photo and location would at least help you get through the first round of vetting. Did you drive in? Can you stay in your car in the worst case?
There are some Boomers who are in DC who may legitimately not know about this site (yet).
My advice is to look in Arlington.
Post a photo of the decal you saw and its location please.
We're in VA just over an hour from D.C. and we're rolling out in around 8 hours so I can't help but I think posting the photo and location would at least help you get through the first round of vetting. Did you drive in? Can you stay in your car in the worst case?