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. [structural elements and components for structural elements]
8. structural elements
9. [spanning and projecting structural elements]
10. [arches and arch components]
11. arches
12. [arches by form]
13. [arches by form: construction]

Anotations

Scope note:

Masonry constructions whose archlike form is created by cantilevering successive courses inward beyond the preceding until they meet at the span's midpoint; thus the courses are set horizontally, not radially; not true arches.