Down with ‘op. cit.’

I note with interest that the Journal of the Medical Library Association (JMLA) uses a particular style of referencing for the articles that it publishes. Every reference in an article receives a fresh number each time it is mentioned in the text. This means that if authors refer to the same references somewhat further on in their papers then those references are given new, different numbers. The Latin abbreviation “ibid.” appears in the reference list if the authors are referring to the same paper they have just cited or “op. cit.” if they are referring the reader back to an earlier citation. This procedure may not matter much for the reader when references are few. It can matter a lot, however, when authors refer to the same references several times. At least two difficulties arise with lengthy reference lists presented in this style. First of all the list gets much longer than it needs to be. For example, in an article I submitted to the JMLA [1], providing each reference with a fresh number increased the number of references from 46 to 102. Second, the procedure is complicated for the readers. For example, a reader interested in a particular reference has to go first from the number given in the text (say 27) to that number in the list and, then, if this reference has been cited earlier, to search back up the non-alphabetical list for the name(s) of the author(s) of this particular article (e.g., perhaps now number 3). Furthermore, when there are several citations to different papers written by the same authors, every subsequent “op. cit.” reference has to be further clarified by supplying the title of the particular paper being referred to—a tacit admission that the system is inadequate. In my view, any reference system used in journal articles should be designed to help the reader find the information needed [2]. The system currently in use the JMLA fails in this respect.