Among the entries or access points assigned to a catalog record, one is designated as the main entry. The other access points are called added entries. The record that bears the main entry represents a complete catalog record of the item and is presented in the form by which the item is to be uniformly identified and cited.
In recent year, the concept of main entry has been challenged. It is questioned whether, in a multiple-entry file, the main entry has any real significance. Some feel that since the user can retrieve the catalog record through any of the entries, they have equal value.
Nonetheless, in AACR-2, the concept of main entry is still maintained as being valid at least under the following circumstances:
1. In making a single entry listing.
2. In making a single citation for a work (as required for entries for related works and for some subject entries).
3. In assigning uniform titles and in promoting the standardization of bibliographic citation.
Chapter 21 of AACR-2 is devoted to the choice of access points and the designation of the main entry.