walls, doors and windows
DW in a kitchen floor plan means Dish Washer.
Parallel hidden lines
OTS means Open to SKy
The outlet symbol is typically represented by a small circle with two parallel lines on a floor plan. It is usually located near walls or in specific areas where electrical outlets are installed.
Look more closely. Does it say "AFF" perhaps? That means "above finished floor".
Work in Revision. This means that this area of the drawing may change.
What does KS mean on a floor plan? Knee Space
warming oven ... only on a fancy floor plan!
Pianta in Italian means either "floor plan" or "(botanical) plant" in English.
I think it means "return air" - a duct for a ducted heating and/or cooling system
"DB" on a floor plan commonly stands for "dining room" or "dining area." It indicates the space in the floor plan designated for dining activities.
Floor plan mean Scottish plan. It shows the distance of room from the floor and physical appearance of room walls and all other features of rooms.