Doing Research at the Library of Congress

IIA. Three Basic Principles of Library of Congress Subject Headings

There are three principles to keep in mind when using the LCSH system:

1. uniform heading
2. scope-match level of coverage
3. specific entry

These arcane-sounding concepts can enable researchers to be much more efficient in their use of the Library's catalog. (In a closed-stacks library in which direct browsing of the bookshelves is not allowed, efficient use of the catalog is particularly important.) The best retrieval comes from exploiting the internal structure of the cataloging system; these principles define that structure.