What must be applied to headings for Word's table of contents feature to function?

For Word's table of contents feature to function properly, heading styles must be applied to the text intended to be included in the table of contents. When you use heading styles (such as Heading 1, Heading 2, etc.), Word recognizes these headings as key points in your document. This allows the program to automatically generate a table of contents that lists the headings along with their corresponding page numbers.

Using heading styles provides structure to the document, enabling the table of contents to reflect the organization of the content accurately. By applying these predefined styles, the feature can easily categorize and retrieve the headings necessary for creating a coherent table of contents. Other options, such as footnote styles, paragraph styles, and character styles, do not serve this specific purpose and thus do not facilitate the automatic generation of a table of contents in the same way that heading styles do.