Beyond the Standard: How a Growing Number of US Libraries Are Building Their Own Subject Vocabularies

Across the United States, a quiet but consequential shift is underway in how libraries organize and surface their collections. Faced with LCSH's documented limitations in representing specific communities, disciplines, and local contexts, a growing cohort of academic, tribal, community, and specialized libraries has moved to supplement or replace the standard vocabulary with systems of their own design. Whether this trend signals a productive diversification or a fragmentation that ultimately harms users remains one of the more contested questions in contemporary library practice.

The Pressure That Built to a Breaking Point

For most of its history, LCSH's position as the dominant subject vocabulary in US library cataloging was effectively unchallenged. The economies of shared cataloging—the ability to import bibliographic records from OCLC and other utilities rather than creating them from scratch—made deviation from the standard vocabulary a significant institutional cost. Libraries that assigned non-standard headings risked losing the efficiency benefits of cooperative cataloging while gaining local consistency that benefited only their own patrons.

That calculus has shifted over the past two decades for reasons that are both technical and political. On the technical side, improvements in local catalog systems and discovery interfaces have made it increasingly practical to maintain parallel or supplementary vocabularies alongside LCSH without entirely forgoing the benefits of shared cataloging. A library can import a standard bibliographic record from WorldCat and then add locally assigned subject terms that appear in its own discovery layer without altering the shared record.

On the political side, a sustained and increasingly organized critique of LCSH's treatment of marginalized communities has generated both the motivation and, in some cases, the institutional support for developing alternatives. The work of scholars like Sanford Berman, whose decades-long campaign against LCSH's biased terminology laid groundwork for contemporary reform efforts, has found new audiences in a library profession increasingly attentive to questions of equity and representation.

The Tribal Libraries Leading the Way

Among the most substantive departures from LCSH have come from libraries serving Indigenous communities. The Brian Deer Classification System, developed in Canada and adopted by a number of tribal libraries in the United States, organizes materials according to Indigenous knowledge structures rather than the Western disciplinary frameworks that underpin both LCSH and the Library of Congress Classification. For collections centering Native American history, culture, and knowledge, the system offers organizational logic that reflects how community members actually conceptualize their own materials.

In the US context, the Xwi7xwa Library at the University of British Columbia has served as a model for tribal and Indigenous-focused libraries seeking to move beyond standard Anglo-American cataloging frameworks, even as its direct influence has been felt most strongly in the Pacific Northwest. Several tribal college libraries affiliated with the American Indian Higher Education Consortium have undertaken similar projects, developing local subject heading supplements that incorporate tribal languages, place names, and culturally specific concepts that LCSH either lacks entirely or represents through terminology the communities themselves find objectionable.

These projects are not without cost. Developing and maintaining a local vocabulary requires ongoing cataloging labor and a commitment to vocabulary governance that many small tribal libraries struggle to sustain. The tradeoff—greater representational accuracy against reduced interoperability with mainstream library systems—is one that each institution must weigh according to its own mission and community needs.

Academic Libraries Carving Out Disciplinary Niches

The trend is not confined to Indigenous and community libraries. A number of specialized academic libraries have developed supplementary vocabularies to address LCSH's inadequacy in particular research domains. Law libraries have long maintained parallel systems through the Library of Congress's own Subject Headings for Children and the American Association of Law Libraries' resources, but the pattern extends to other fields as well.

The Harvard Law School Library's Nuremberg Trials Project developed a specialized subject vocabulary for its digitized collection of Nuremberg trial materials, recognizing that LCSH lacked the granularity needed to support serious legal and historical research in that domain. Medical libraries affiliated with academic health centers have similarly augmented LCSH with MeSH (Medical Subject Headings) and locally developed terms for emerging clinical and research areas that neither standard vocabulary adequately covers.

Archives and special collections have perhaps gone furthest in this direction. The Describing Archives: A Content Standard (DACS) framework and the related development of local subject schemes at institutions including the Smithsonian, the National Archives, and numerous university special collections reflect a recognition that archival materials—particularly those documenting community histories, social movements, and non-institutional actors—require descriptive approaches that LCSH was never designed to provide.

The Interoperability Question

Critics of local vocabulary development raise a concern that deserves serious engagement: fragmentation. The value of LCSH as a shared standard derives precisely from its universality. When a researcher searches for materials on a topic across multiple library catalogs or in a national discovery system, LCSH's consistency enables results that transcend institutional boundaries. A proliferation of local vocabularies, however locally appropriate, risks recreating the pre-standardization landscape in which materials were effectively invisible beyond the walls of the institution that held them.

Linked data frameworks offer a partial response to this concern. Initiatives such as the Library of Congress's own linked data service and the broader BIBFRAME project are designed to enable mappings between different controlled vocabularies, potentially allowing a search conducted in LCSH terms to retrieve materials cataloged under equivalent terms in a local scheme. In theory, this architecture supports both local specificity and cross-institutional discoverability.

In practice, linked data implementation remains uneven across US libraries, and the mappings between vocabularies are only as good as the intellectual work that goes into creating them. Establishing reliable equivalencies between LCSH headings and locally developed terms requires sustained collaboration between the institutions maintaining different vocabularies—collaboration that does not happen automatically and for which there is currently no well-established infrastructure.

A Field in Productive Tension

What emerges from surveying these developments is a picture of a field genuinely wrestling with competing goods: the efficiency and discoverability benefits of standardization on one side, and the representational accuracy and community responsiveness of local control on the other. Neither pole represents a complete answer.

Libraries that have moved most successfully beyond LCSH have generally not abandoned the standard vocabulary entirely. They have developed hybrid approaches that maintain LCSH for interoperability purposes while layering local or community-specific terms that serve their particular patrons more accurately. This is not a permanent solution to LCSH's structural limitations, but it is a pragmatic accommodation that many institutions are finding workable.

The deeper question—whether the Library of Congress will respond to this pressure by accelerating vocabulary reform, or whether local alternatives will gradually displace the standard in specific domains regardless of what the central authority does—remains open. What is clear is that the era in which LCSH's dominance went effectively uncontested has ended. The next chapter of subject cataloging in US libraries will be written by a larger and more diverse group of authors than any previous one.