Definition: Out of Bounds

All areas outside the boundary edge of the course as defined by the Committee. All areas inside that edge are in bounds.

The boundary edge of the course extends both up above the ground and down below the ground:

This means that all ground and anything else (such as any natural or artificial object) inside the boundary edge is in bounds, whether on, above or below the surface of the ground.
If an object is both inside and outside the boundary edge (such as steps attached to a boundary fence, or a tree rooted outside the edge with branches extending inside the edge or vice versa), only the part of the object that is outside the edge is out of bounds.

The boundary edge should be defined by boundary objects or lines:

Boundary Objects: When defined by stakes or a fence, the boundary edge is defined by the line between the course-side points of the stakes or fence posts at ground level (excluding angled supports), and those stakes or fence posts are out of bounds.
When defined by other objects such as a wall or when the Committee wishes to treat a boundary fence in a different way, the Committee should define the boundary edge.
Lines: When defined by a painted line on the ground, the boundary edge is the course-side edge of the line, and the line itself is out of bounds.
When a line on the ground defines the boundary edge, stakes may be used to show where the boundary edge is, but they have no other meaning.

When stakes are used to define or show the boundary edge, they are boundary objects.

Boundary stakes or lines should be white.