Content publishers, libraries, software developers, technical writers, abstractors, editors, database producers, data searchers, product developers, academic professionals, researchers, and readers all use indexes on a daily basis, even if they’re not always aware of it. Indexing and its basic principles underlie search systems, web-based finding aids, database organization, ebook information retrieval, and back-of-the-book indexes. The American Society for Indexing (ASI) advocates, educates, and provides the central resource for indexing in the United States, in affiliation with numerous international indexing organizations.