Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Visual and Verbal Communication (hierarchy name)
4. Information Forms (hierarchy name)
5. information forms (objects)
6. document genres
7. [documents by function]
8. [identifying markings and symbols]
9. marks (identifying markings)
10. [marks by function]

Anotations

Scope note:

Official marks stamped on mail, sometimes serving as cancellations, that indicate the place, date, and sometimes the time that the postal system accepted custody of the item; use "cancellations" only for official defacements of postage stamps to prevent their reuse.