It is true that they seldom have formal training in the intricacies of the cataloguer’s art: they are not necessarily up on the elaborate Anglo-American cataloguing rules, nor are they current concerning the periodic “Rrs, or Rule Interpretations, issued by the Library of Congress, which—like hermeneutical dispatches from the I.R.S. or the Financial Accounting Standards perplexing cases in classification as they emerge. Most operators have had no library-school courses in the Dewey Decimal system (still thriving, by the way, and very big in Europe), or the “Sears List of Subject Headings,” or Cutter numbers, or the abbreviational niceties of the International Standard Bibliographic Description (I.S.B.D.) format—but they do apparently pick up a great deal as they go.