 It allows the mixing of formats, provided that the result is clear and consistent.For instance, the fifteenth edition of "The Chicago Manual of Style" permits the use of both in-text citation systems and/or footnotes or endnotes, including use of "content notes"; it gives information about in-text citation by page number (such as MLA style) or by year of publication (like APA style); it even provides for variations in styles of footnotes and endnotes, depending on whether the paper includes a full bibliography at the end.Two types of citation styles are provided.