An added entry is “an entry, additional to the main entry, under which a bibliographical entity is represented in a catalogue”. The additional entries supplement the main entry by providing an additional approach to documents listed in the catalogue. Sometimes, added entries are called secondary entries. These have their own importance. These are prepared for subordinate authors like joint authors, editors, translators, and illustrators. These are also prepared for title, series, and subject. However, a reference is prepared for the editor of a series. AACR has provided rules for their preparation.
Harrod’s Librarians Glossary define Added Entry as “A secondary catalogue entry, i.e. any other than the Main entry with the addition of a heading for subject, title, editor, series, or translator, and in the case of music, for arranger, librettist, title, medium, form, etc. It must not be confused with a Cross reference. “