In a Chicago style bibliography, each reference is formatted with a hanging indent. This means that the first line of each reference is flush with the left margin, while subsequent lines are indented. The amount of indentation used for each line should be equal to the width of the first line. For example, if the first line of a reference is 1 inch long, then all subsequent lines should be indented 1 inch.
Hanging indents are used in Chicago style bibliographies to visually separate references from one another and to make it easier to read and navigate the bibliography.