The Footnote tab is only available when the Insert Link As property is set to Footnote, and defines how the links in the Hypertext links tab will be converted into footnotes in the Word document.
Note: Only topic links are converted into footnotes, Internet URLs are ignored. The topics specified do not have to be in the book being published. The Topic Heading is ignored, only the topic text is inserted as a footnote.
Footnote Numbering
Allows you to choose the type of numbering used for footnotes - Automatic or Custom.
Automatic Numbering
Allows you to choose from a variety of automatic numbering styles used to number your footnotes.
Custom Numbering
Defines the custom mark that will be used to mark your footnote. Choose Symbol to select a special character or symbol.