Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Components (hierarchy name)
4. components (objects parts)
5. [components by specific context]
6. architectural elements
7. [openings and opening components]
8. openings (architectural elements)
9. [openings by form]
10. [gateways and gateway components]
11. gateway components
12. [gates and gate components]
13. gates (swinging barriers)

Anotations

Scope note:

Restraining structures incorporating a barrier that is raised or pushed aside at the start of a race, to ensure a simultaneous start for all competitors or to ensure consistent timing of each competitor. Examples are used in horse racing, foot races, downhill skiing, and other sports.