Prose craft
Metafiction
A form of fiction that emphasizes its own narrative structure, reminding the audience they are reading a fictional work.
Metafiction is "a form of fiction that emphasizes its own narrative structure in a way that inherently reminds the audience that they are reading or viewing a fictional work." It is "self-conscious about language, literary form, and storytelling," and its works "draw attention to their status as artifacts." William H. Gass coined the term in 1970, but the practice is far older: Chaucer's Canterbury Tales, Part Two of Don Quixote and Sterne's Tristram Shandy all step outside themselves, and the mode flourished in the 1960s, in Lost in the Funhouse, Pale Fire and Slaughterhouse-Five. It is often "a form of parody or a tool to undermine literary conventions."
For novelists the device spans a scale: a narrator's direct address, the prose face of breaking the fourth wall, at one end, a whole architecture of nested tales, the story within a story, at the other. Its price is distance, since readers kept conscious of the machinery must be given something the machinery is worth, wit, parody or genuine unease. Web-serial writers already run a metafictional channel in the author's note, and keeping the registers separate, commentary beside the chapter rather than inside it, protects the story's own contract.