Does anyone know if BYO is allowed in Maryland?
It may vary per jurisdiction. Owner’s discretion in Montgomery County.
It is allowed, although not widely practiced. Mostly, although not exclusively, at places without liquor licenses.
Bruce,
Restaurants may purchase a license allowing BYOB. Of course, the willingness to do so is not overwhelming. In the Baltimore metro area, maybe 1 in 4 have the BYOB license.
An excellent restaurant in Bethesda that allows corkage is Bistro Provence