How to distinguish between the left open door and right inside the door

People standing inside and outside the room are opposite

1, left open the door: people do not have a key in the room to open the door, the door locked in the door on the left, to the indoor direction to open the door. People open the door with a key in the room, the door locked in the door on the right, to the indoor direction to open the door. 2, right inside the door: people do not have the key to open the door in the room, the door locked in the door on the right, to the indoor direction to open the door. People open the door with a key in the outdoors, the door locked in the door on the left, to the indoor direction to open the door.

The door of the door is on the right side (ie, the handle is also the right side) is the right open, the door of the leaves in the left, then left open.