 The various guides thus specify order of appearance, for example, of publication date, title, and page numbers following the author name, in addition to conventions of punctuation, use of italics, emphasis, parenthesis, quotation marks, etc., particular to their style.A number of organizations have created styles to fit their needs; consequently, a number of different guides exist.Individual publishers often have their own in-house variations as well, and some works are so long-established as to have their own citation methods too