ODLIS is designed as a hypertext reference resource for library and information science professionals, university students and faculty, and users of all types of libraries. The primary criterion for inclusion is whether a librarian or other information professional might reasonably be expected to know the meaning of the term in the context of his/her work. A newly coined term is added when, in the author's judgment, it is likely to become a permanent addition to the lexicon of LIS. The dictionary reflects North American practice. However, because ODLIS was first developed as an online resource available worldwide, with an e-mail contact address for feedback, users from many countries have contributed to its growth, often suggesting additional terms and commenting on existing definitions. Expansion of the dictionary is an ongoing process.

Broad in scope, ODLIS includes not only the terminology of the various specializations within LIS but also the vocabulary of publishing, printing, binding, the book trade, graphic arts, book history, literature, bibliography, telecommunications, and computer science when, in the author's judgment, a definition might prove useful to librarians and information specialists in their work. Entries are descriptive, with examples provided when appropriate. The definitions of terms used in the Anglo-American Cataloging Rules follow AACR2 closely and are therefore intended to be prescriptive. The dictionary includes some slang terms and idioms and a few obsolete terms, often as See references to the term in current use. When the meaning of a term varies depends on the field in which it is used, priority is given to the definition that applies within the field with which it is most closely associated. Definitions unrelated to LIS are generally omitted. As a rule, definition is given under an acronym only when it is generally used in preference to the full term. Alphabetization is letter-by-letter. The authority for spelling and hyphenation is Webster's New World Dictionary of the American Language (College Edition). URLs, current as of date of publication, are updated annually