Thanks so much for your help! I have summarized the responses below (actually, Cheryl, I left yours in full because I thought that some other "newbie" might benefit from it). Actually, I am not really a 'newbie," but I might as well be when it comes to cataloging. Cordially, John Roy David Christensen Recommended Cutter's Tables http://www.kfupm.edu.sa/library/cod-web/Cutter-numbers.htm Gene Kinnaly, Program Specialist, New Books Project, Cataloging in Publication Division, Library of Congress LC's Subject Cataloging Manual: Shelflisting, available on Cataloger's Desktop. Memo G60 on call numbers includes the Cutter table used by LC staff to construct LC call numbers. Cheryl Boettcher Tarsala, Adjunct Assistant Professor, LEEP Program, Graduate School of Library and Information Science, University of Illinois at Urbana-Champaign LC Cutters are almost infinitely mutable. You probably already have the little Cutter table that goes with LCC. If not, there are many versions copied on the web, like this one: http://staff.library.mun.ca/staff/toolbox/tables/lccutter.htm If you look, you can see that your example concurs directly with the table, .R6 for Ro, then adding 7 for an additional letter, in this case "S." If you are checking copy, however, you'll discover that many LC-assigned cutters simply do not match the official table. This is because the table is only a starting point. LC's choice of cutters is entirely *situational,* based on previous cutter number assignments in any given range of the LC classification. (If you have the Chan textbook, there's one important paragraph, at the top of page 345: "Each entry must be added to the existing entries in the shelflist is such a way as to preserve alphabetical order in accordance with filing rules." This trumps the table) So the table is only a *starting point,* fitting into the existing shelflist is the key. As a practicing cataloger, you can take this two ways: either you forget about the wider world of LCC and just make sure it's unique for your library--adjusting the number decimally up or down--or you can go to the LC online catalog and look the numbers in their call number browse and make your numbers fit into their alphabetical sequence: http://catalog.loc.gov/ I think in the past, especially in small collections, nobody really cared about making cutters that fit into a virtual, national shelflist in this way--or even into one's own collection, but it may save time in the future because you'll avoid clashing numbers on future works with LC-assigned cutters. If you still have general questions about LCC, Chapter 13 of Chan's Cataoging and Classification 1995 is an excellent reference source and rereading it now will have much more relevance than back in cataloging class! Beth Picknally Camden, Acting Director, Content Management Services, University Library Recommended Cutter's Tables Wesbite http://130.15.161.74/techserv/lc-cut.html