----------------------------Original message----------------------------
  This message is being cross-posted to MAPS-L and GOVDOC-L.  We
  are interested in finding out how other libraries are removing
  records from their online catalogs for superseded 7 1/2-minute
  topographic maps (the I 19.81's).  Clearly, over the course of
  years, thousands of these maps "replace" or supersede early
  editions.  According to the GPO's _Superseded List_, libraries
  may discard the old maps "if revised", but don't the thousands
  of online records remain?  Also, does anyone know when GPO
  began cataloging 7 1/2-minute topos in OCLC?  Please respond to
  [log in to unmask], not to the list.  Thank you!
 
  Michael Knes, Map Specialist
  Cass Hartnett, Documents Librarian
  Detroit Public Library
  5201 Woodward Ave.
  Detroit, MI  48202
  (313) 833-1445