Meta-reference is a special type of self-reference that can occur in all media or media artifacts, for instance literature, film, painting, TV series, comic strips, or video games. It includes all references to, or comments on, a specific medium, medial artifact, or the media in general. These references and comments originate from a logically higher level (a "meta-level") within any given artifact, and draw attention to—or invite reflection about—media-related issues (e.g. the production, performance, or reception) of said artifact, specific other artifacts (as in parody), or to parts, or the entirety, of the medial system. It is, therefore, the recipient's awareness of an artifact's medial quality that distinguishes meta-reference from more general forms of self-reference. Thus, meta-reference triggers media-awareness within the recipient, who, in turn "becomes conscious of both the medial (or "fictional" in the sense of artificial and, sometimes in addition, "invented") status of the work" as well as "the fact that media-related phenomena are at issue, rather than (hetero-)references to the world outside the media." Although certain devices, such as mise-en-abîme, may be conducive to meta-reference, they are not necessarily metareferential themselves. Similarly, innately metareferential devices, such as metalepsis, are to be seen as special cases of meta-reference. The terms meta-reference and metalepsis can, therefore, not be used synonymously. History of the concept and the term While meta-reference as a concept is not a new phenomenon and can be observed in very early works of art and media not tied to specific purposes (e.g. Homer's invocation of the muses at the beginning of the Odyssey in order to deliver the epic better), the term itself is relatively new. Earlier discussions of metareferential issues often opt for more specific terminology tied to the respective discipline. Notable discussions of meta-reference include, but are not limited to, William H. Gass's and Robert Scholes's exploration of metafiction, Victor Stoichita's examination of early modern meta-painting, and Lionel Abel's investigation of metatheatre. In the context of drama, meta-reference has also become colloquially known as the breaking of the fourth wall. The first study to underscore the problem resulting from the lack of cohesive terminology, as well as the necessity to acknowledge metareference as transmedial and trans-generic phenomenon, was published in 2007 by Hauthal et al. Publications by Nöth and Bishara as well as Wolf followed suit, raised similar concerns, included case studies from various media, coined and helped establish the more uniform umbrella term