Times were, everyone in Virginia understood that if a charge was "nol prossed" (motion for nolle prosequi) it could come back, but if it was dismissed it was gone forever. Of course, this was a different terminology than the feds use and apparently it confused some people (after all, how many of us were taught the fed rules of procedure at law school rather than the proper common law ones which Virginia, that rock of the common law, has maintained?).
So now we have a statute setting out trial procedure as to a dismissal:
§ 19.2-265.6. Effect of dismissal of criminal charges.
No dismissal of any criminal charge by a court shall bar subsequent prosecution of the charge unless jeopardy attached at the earlier proceeding or unless the dismissal order explicitly states that the dismissal is with prejudice.
(2007, c. 419.)
Why did this change come about? Maybe it's because the General Assembly meets every year and doesn't have enough important work to fill its time with. Maybe it's because someone lost a case when they said motion to dismiss rather than motion to nol pross. Whatever the cause, it confuses judges if you say it. Go on, I dare you. Walk up to a bench in the Commonwealth and ask for a dismissal with prejudice. The judge and attorney on the other side will give you the strangest looks . . .