Vocabulary control is of particular importance not only for indexes compiled for multiauthor texts, but also for the indexes that appear at the end of the volume year in medical journals. In general, the rules and guidelines that apply to back-of-the-book indexes also apply to journal indexes. Where, in specialty journals, nomenclature is in flux or variable, indexers should follow the style and recommendations of their publishers or editors, cross-referencing to preferred terms or forms of entry rather than double-posting. Journal indexes differ from book indexes in basing index entries largely on title and abstract information, which summarizes an article’s main topics, and usually do not include entries for subject matter that is secondary or incidental within the text of the article. Locators are given as an article’s beginning page or the article’s page range and sometimes include issue number or date. Publishers may specify, or indexers may choose to make, general entries for the type of study (“Randomized Trial,” “Review”), for the population group studied (“Child,” “Men,” “Women,” Elderly”), and other entries for recurring article types or topics. These entries should be made consistently issue by issue throughout the volume year. If, for example, “Adverse Reactions” is established as an general index entry, it should be entered for each article examining a specific reaction regardless of whether the term adverse reaction appears in the title or abstract.