Folklore

When “folklore” is used as a subdivision in a Library of Congress Subject Heading under a topic or ethnic group, does it refer to the folklore of the topic/ethnic group, or to folklore about the topic/ethnic group?
A few years ago Library of Congress Subject Headings introduced the concept of a “form” subject subdivision, as opposed to a “topical” subject subdivision. The “form” subdivision is used to describe what the book IS; the “topical” subdivision is used to describe what the book is ABOUT. The difference is coded into the cataloging record. In MARC (the computer design used by libraries in the U.S.) what the book IS is coded into a subfield “v” in the subject heading, and what the book is ABOUT is coded into a subfield “x” in the subject heading. If your computer system used this coding to differentiate the subdivisions you could tell how the term was used.
This having been said, there are instructions for assigning subject headings to folklore materials. Library of Congress instructs us to assign the following headings to books on folklore:

• $a [Ethnic, national, or occupational group] $z [place] $v Folklore . (Example: $a Indians of North America $z Texas $v Folklore)
• $a [theme] $x Folklore . (Example: $a Lizards $x Folklore)
• $a [heading(s) for specific folklore genre(s)] $z [place]. (Example: $a Legends $z Texas)
• $a Folklore $z [place]. (Example: $a Folklore $z Texas)
• $a [place] $x Social life and customs. (Example: $a Texas $x Social life and customs)
• $a [other topics, as applicable] (Example: $a Storytelling $z Texas)
• NOTE: Not all of these subject headings are assigned to each book.

For example, a book may not specify a particular theme or topic.) Using the instructions above, if one had a book on lizards as a theme in the folklore of the Navajos, the appropriate subject headings would be:

• $a Navajo Indians $v Folklore. (a subfield “v” is used because the book IS their folklore, not ABOUT their folklore)
• $a Lizards $x Folklore. (a subfield “x” is used because the book is ABOUT lizards in folkore, not the folklore of the lizards)
• $a Legends $z Southwest, New.

One could also add: “$a Folklore $z Southwest, New” but this heading is broader than the actual scope of the book.