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. [architectural elements by building type]
8. fortification elements
9. fortification openings

Anotations

Scope note:

Small openings (as in walls or parapets), often with deeply splayed jambs, through which small arms may be discharged; for similar openings to admit light and air or to permit observation, use "loop windows."