In pre-coordinated CV systems, multiple concepts are brought together in one term. An illustrative example is the Library of Congress Subject Headings (LCSH), which yield entries such as: "Insurance, Unemployment --Switzerland --Statistics." This method allows for disambiguation of the relationship of the concepts in the term that might not be possible in post-coordinated systems, such as whether a term is a qualifier of another. In post-coordinated or faceted systems, concepts are kept broad and separate and selected and joined in the process of searching with Boolean operators. A representation of the above LCSH in this system could be "Insurance AND Statistics AND Switzerland AND Unemployment" – note that entry order in the query has no relevance here. An example of such a system is the American Psychological Association's Thesaurus of Psychological Index Terms.
