To the person who found me by searching for “can you get a parking ticket in dc for having va tag where there are no sign”:
Yes. If it involves a non-moving car, you can get a ticket for it in DC.
If you remember that rule, you may save yourself a few parking tickets. I won’t say that you will save yourself from getting any parking tickets, because that’s impossible. But you can perhaps minimize them by assuming that you will always be ticketed. You will usually be right.
Anyway, I suggest you contest any ticket you might receive. It makes you feel better, and you can do it by mail, so it hardly costs anything.