WHAT MLS SYSTEM AM I IN?
Depends on the area you live:
MRIS - Northern Virginia, MD, DC and surrounding areas
REIN - Virginia Beach/Hampton Roads, etc
WAAR - Williamsburg and surrounding areas,
CVR - Richmond area,
RV - Roanoake Valley area,

HRAR - Harrisonburg and Rockingham,
CAAR - Charlottesville area,
CBRAR - Chesapeake Bay Rivers Association
NRV - New River Valley area to name just a few.
LAR - Lynchburg City
CAR - Ocean City Maryland


Here is a complete breakdown of all the Virginia Cities in alphabetical order and the MLS that covers that city.
Here is a complete breakdown of Each MLS and the Cities covered by the MLS.