Controlled vocabularies may aid coordination within systems while simultaneously hindering coordination across them (Lancaster , 181). Many solutions to this quandary have been proposed, but most of these assume a context in which there is a strong central organization able to impose a coordinating superstructure. In decentralized contexts, exhaustive full‐text indexing has largely supplanted attempts to achieve cross‐system compatibility of controlled vocabularies. We report on an approach to achieving some degree of cross‐system compatibility of controlled vocabularies in a context where 1) there is no centralized control, and 2) full‐text indexing alone is inadequate for bringing together related documents.