Dictionary.net

A single citation covering several articles of various degrees of specificity or a single citation covering papers presented at a meeting. A subject overall refers to a series of articles on a single subject; a congress overall refers to papers presented at a formal local, regional, national, or international gathering; a society overall refers to papers presented at an annual, semi-annual, monthly, weekly, or other meeting of a society, academy, institute, hospital, etc. The publication type may be used for a single citation with or without the additional indexing or cataloging of individual papers. The individual papers, however, are not labeled OVERALL.