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 element components
9. arch, dome or vault components
10. ribs (dome or vault components)

Anotations

Scope note:

Ribs which span at right angles to the longitudinal axis of the space being spanned, dividing it into bays or compartments; for arches separating the bays of vaults, particularly in a groin- or barrel-vaulted space, use "transverse arches."