Containment

From IFWiki

The nesting of one object inside another. When a room contains objects (e.g. tables, cabinets, pedestals, canvas bags), which can, in turn, contain other objects or even secret levels.

Knowing how objects are stacked inside one another (and which objects are open or transparent) allows the game to calculate, for instance, whether a light source is visible to the player.

See also scope.

Code Compare: Container
ADRIFT 4:	Object is a container
Inform 6:	The container attribute
Inform 7:	The container kind
TADS 3:	The Container class