The number of headings assigned to each work depends on the nature of its content and the structure of available subject headings. Certain categories of works are generally not assigned any subject headings. Many works are assigned only one heading. In other cases, multiple headings are required. In general, no more than ten headings are assigned to any one work.

26.0 Reference

26.1 Works requiring no subject headings

26.2 Uniform heading vs. duplicate entry

26.3 Single entry vs. doubling

26.4 Works on single topics

26.5 Works on single topics with multiple elements or aspects

26.6 Works on multiple topics

See also:

A. General Guidelines for Assigning Subject Headings