The J behind the document stands for Journal, and M stands for Monograph. Common identification of other document types: Proceedings [c]; Dissertation [D]; Standard [S]; Report [R]; Patent [P]; Newspaper [N]. Extended information The `M after the document stands for Monograph, and J stands for Journal. Common other reference type identification codes: M: Monograph; C: Collection; N: Newspaper article; J: Journal article; D: Degree; R: Report; S: Standard; P: Patent; A: Article of precipitated documents in monographs and collections of papers; Z: Other unexplained documents.