1. Toss scallops with flour and marjoram.
2. Heat oil in a large skillet over medium-high heat. Tap excess flour off scallops and cook until fully opaque, flipping once (2-3 minutes per side). Remove scallops and set aside.
3. Add wine and vinegar to skillet to deglaze. Stir with a whisk until slightly thick (3 minutes). Stir in scallops to coat.
4. Serve immediately, garnished with parsley if desired.