Because the official MLA Handbook offers no specific instructions regarding the format of an epigraph, writers are left to devise their own rules, compatible with MLA style. Many writers find it helpful to study MLA standards regarding the formatting of quotations and headings in order to get a feel for what should be appropriate formatting for epigraphs.
By the Numbers
Considering MLA rules already in place regarding similar types of content, it is advised that epigraphs be once double-spaced beneath the title of the written work and indented two inches from the paper's edge on each side. If an epigraph precedes an entire book, such as a novel, it is not uncommon to find the text on its own page, usually immediately after the book's title page. What's more, book chapters can each have their own individual epigraphs appearing, more conventionally, under the chapter number or title.
While it is commonplace for essays and research papers written in MLA style to be double-spaced, epigraphs are usually single-spaced so as not to take up valuable room, as well as to individuate the text and its function from the rest of the copy on the page. Some writers take the singling out of the epigraph further by italicizing the text or making it one or two font sizes smaller than the rest of the words on the page.
It is vital that the author of the epigraph's content follow the epigraph, even if that author is unknown or "Anonymous." The name should be typed immediately below the epigraph, indented to the right, usually preceded with an em-dash. Furthermore, the source of the epigraph is always included on a Works Cited page, if one is included.
Bending the Rules
Occasionally, writers have produced their own epigraphs, citing fictional characters from their own works, individuals who might or might not have written or said the words in the original book, story or poem in which they were featured. For example, the author of the verses that precede F. Scott Fitzgerald's "The Great Gatsby" is none other than Thomas Parke D'Invilliers, a character from another Fitzgerald novel, "This Side of Paradise."