Explanatory or content notes are used to provide explanations, comments, or any supplementary material related to the primary content that might otherwise make the text too lengthy or difficult to read. These notes may contain supplementary references. They should be cited in the text or in an appendix. They can also be used to highlight important issues arising from the text itself. An explanatory note is like a footnote but written as part of the body of the text instead of at the end. Footnotes are useful for including bibliographies, lists of definitions, quotes, or any other material that doesn't fit into the main body of the book. An explanatory note is best used for material that would take longer than a footnote; for example, an overview section or an appendix. Exemplary uses of explanatory notes include explaining technical terms or concepts that may not be familiar to everyone who reads the book, providing sources for facts mentioned in the text, or pointing out interesting or noteworthy examples. The presence of an explanatory note is indicated by a vertical space after the sentence and a second horizontal line before the note. The explanatory note should be typed on a separate sheet of paper and inserted into the manuscript immediately after the sentence it explains. It should begin with the word "Note:" and should be signed by the author of the surrounding text. The note should be numbered accordingly so that it does not disrupt the flow of the text.