For cartographic materials, subject headings are assigned to provide access to physical areas, topical focuses, special cartographic forms, and persons associated with the area(s) or topic(s) represented in the item. Form of material may also be represented by either form headings or form subdivisions under geographic, topical, or personal headings. There is no limit to the number of headings that may be assigned to an item. The heading which most closely corresponds to the class number is assigned as the primary heading.

42.2 Reference

42.21 Headings for physical areas

42.22 Topical headings

42.24 Form headings

42.25 Subdivisions

See also:

42.0 Works in special subject areas